U.S. patent application number 14/856081 was filed with the patent office on 2016-03-24 for non-metallic semiconductor quantum dot and method of carrying out chemical reaction or photoluminescence reaction by using the same.
The applicant listed for this patent is NATIONAL CHENG KUNG UNIVERSITY, National Cheng Kung University Hospital. Invention is credited to Hai-wen CHEN, Chung-jen CHUNG, Wei-lun HUANG, Wu-chou SU, Hsisheng TENG, Te-fu YEH.
Application Number | 20160087148 14/856081 |
Document ID | / |
Family ID | 55526536 |
Filed Date | 2016-03-24 |
United States Patent
Application |
20160087148 |
Kind Code |
A1 |
HUANG; Wei-lun ; et
al. |
March 24, 2016 |
NON-METALLIC SEMICONDUCTOR QUANTUM DOT AND METHOD OF CARRYING OUT
CHEMICAL REACTION OR PHOTOLUMINESCENCE REACTION BY USING THE
SAME
Abstract
A non-metallic semiconductor quantum dot is provided with a
non-metallic substrate, and has a particle size ranged from 0.3 to
100 nm. A method of carrying out a chemical reaction or a
photoluminescence reaction by using the non-metallic semiconductor
quantum dot is also provided. A redox reaction of a target sample
is carried out, an active substance is generated, or an
electron-hole pair is produced from the non-metallic semiconductor
quantum dot by providing the non-metallic semiconductor quantum dot
with a predetermined energy. Photons are released by the
combination of the electron-hole pair so as to perform the
photoluminescence reaction.
Inventors: |
HUANG; Wei-lun; (Tainan
City, TW) ; SU; Wu-chou; (Tainan City, TW) ;
CHEN; Hai-wen; (Tainan City, TW) ; YEH; Te-fu;
(Tainan City, TW) ; TENG; Hsisheng; (Tainan City,
TW) ; CHUNG; Chung-jen; (Tainan City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NATIONAL CHENG KUNG UNIVERSITY
National Cheng Kung University Hospital |
TAINAN CITY
Tainan City |
|
TW
TW |
|
|
Family ID: |
55526536 |
Appl. No.: |
14/856081 |
Filed: |
September 16, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62052884 |
Sep 19, 2014 |
|
|
|
Current U.S.
Class: |
257/13 ;
204/157.15 |
Current CPC
Class: |
B01J 19/123 20130101;
C09K 11/0883 20130101; C09K 11/00 20130101; B01J 2219/085 20130101;
H01L 31/125 20130101; C09K 11/59 20130101; B01J 23/745 20130101;
B01J 21/18 20130101; B01J 35/004 20130101; B01J 2219/0892 20130101;
B01J 19/10 20130101; B01J 27/24 20130101; B01J 19/087 20130101;
B01J 19/128 20130101; C09K 11/60 20130101; C09K 11/63 20130101;
G01N 33/588 20130101; C09K 11/65 20130101; B01J 19/127 20130101;
B01J 21/06 20130101 |
International
Class: |
H01L 33/06 20060101
H01L033/06; H01L 33/34 20060101 H01L033/34; B01J 19/08 20060101
B01J019/08; B01J 19/12 20060101 B01J019/12; B01J 19/10 20060101
B01J019/10; H01L 31/12 20060101 H01L031/12; H01L 33/24 20060101
H01L033/24 |
Claims
1. A non-metallic semiconductor quantum dot, comprising a
non-metallic substrate, and having a particle size ranged from 0.3
nm to 100 nm.
2. The non-metallic semiconductor quantum dot according to claim 1,
wherein the non-metallic substrate is made of a group IVA
element.
3. The non-metallic semiconductor quantum dot according to claim 2,
wherein the non-metallic substrate is a carbon-based material or a
silicon-based material.
4. The non-metallic semiconductor quantum dot according to claim 3,
wherein the carbon-based material is graphene or graphene
oxide.
5. The non-metallic semiconductor quantum dot according to claim 1,
wherein the non-metallic semiconductor quantum dot comprises at
least one dopant.
6. The non-metallic semiconductor quantum dot according to claim 5,
wherein the dopant is selected from at least one of group IIIA
element, group IVA element, group VA element, group VIA element,
and transition element having an empty d orbital.
7. The non-metallic semiconductor quantum dot according to claim 6,
wherein the dopant is O, N, P, B, Fe, Co, or Ni.
8. The non-metallic semiconductor quantum dot according to claim 5,
wherein the dopant has a doping ratio more than 0 mol % and less
than 50 mol %.
9. The non-metallic semiconductor quantum dot according to claim 1,
wherein the non-metallic semiconductor quantum dot is disc-shaped,
and has a thickness ranged from 0.1 nm to 10 nm.
10. The non-metallic semiconductor quantum dot according to claim
1, wherein the non-metallic substrate has a surface with at least
one functional group selected from H, a group-VA-element functional
group, or a group-VIA-element functional group.
11. The non-metallic semiconductor quantum dot according to claim
10, wherein the group-VA-element functional group is an amino
group, P, or a phosphate group.
12. The non-metallic semiconductor quantum dot according to claim
10, wherein the group-VIA-element functional group is hydroxyl,
carbonyl, carboxyl, or acyl.
13. The non-metallic semiconductor quantum dot according to claim
1, wherein the non-metallic semiconductor quantum dot generates
electron-hole pairs or redox pairs by receiving a predetermined
energy, so as to catalyze a redox reaction or to release photons by
combining the electron-hole pairs to perform a photoluminescence
reaction.
14. The non-metallic semiconductor quantum dot according to claim
13, wherein the predetermined energy is electromagnetic energy,
light, electricity, heat, magnetic energy or ultrasound.
15. The non-metallic semiconductor quantum dot according to claim
13, wherein the photoluminescence reaction releases a light having
a wavelength ranged from 250 nm to 1600 nm.
16. A method of carrying out a chemical reaction by using a
non-metallic semiconductor quantum dot, comprising steps of: (1)
mixing a target sample with the non-metallic semiconductor quantum
dot according to claim 1; and (2) providing the non-metallic
semiconductor quantum dot with a predetermined energy, so that the
non-metallic semiconductor quantum dot generates electron-hole
pairs, and a redox reaction of the target sample is carried out by
the electron-hole pairs; or the target sample or a surrounding
molecule thereof generates an active substance, and a redox
reaction of the target sample is carried out by the active
substance.
17. The method according to claim 16, wherein the predetermined
energy is provided by a laser, a mercury lamp, a visible light, an
ultraviolet light, an infrared light, an endoscopic light, an
X-ray, an ultrasound, an electric field, a magnetic field, a
nuclear magnetic resonance, or a light-emitting diode in the step
(2).
18. The method according to claim 16, wherein the redox reaction in
the step (2) comprises decomposition of the target sample,
polymerization of the target sample, activation of the target
sample, or deactivation of the target sample.
19. The method according to claim 18, wherein the active substance
is a free radical or a peroxide.
20. The method according to claim 19, wherein the free radical is
O.sub.2. or OH.; and the peroxide is H.sub.2O.sub.2.
21. The method according to claim 16, wherein the target sample is
selected from biological cells, bacteria, viruses, parasites, cell
secretions, biological molecules, an organic compound, or an
inorganic compound.
22. The method according to claim 21, wherein the organic compound
is an aromatic compound, alcohol, aldehyde, ketone, acid, amine,
urea, or a polymer thereof.
23. The method according to claim 21, wherein the inorganic
compound is water, nitrite, nitrate or ammonia.
24. The method according to claim 21, wherein the biological
molecules are peptides, nucleic acids, lipids, carbohydrates,
vitamins, hormones, or a polymer thereof.
25. The method according to claim 21, wherein the cell secretions
are extracellular vesicles or extracellular matrix.
26. A method of carrying out a photoluminescence reaction by using
a non-metallic semiconductor quantum dot, comprising steps of: (1)
delivering the non-metallic semiconductor quantum dot according to
claim 1 to a predetermined position; and (2) providing the
non-metallic semiconductor quantum dot with a predetermined energy,
so that the non-metallic semiconductor quantum dot generates
electron-hole pairs, and releases photons by combining the
electron-hole pairs to perform the photoluminescence reaction.
27. The method according to claim 26, wherein the predetermined
energy is provided by a laser, a mercury lamp, a visible light, an
ultraviolet light, an infrared light, an endoscopic light, an
X-ray, an ultrasound, an electric field, a magnetic field, a
nuclear magnetic resonance, or a light-emitting diode in the step
(2).
28. The method according to claim 26, wherein the photoluminescence
reaction has a wavelength ranged from 250 nm to 1600 nm.
29. The method according to claim 26, wherein the method comprises
a step (3) of using the photoluminescence reaction as a signal
source after the step (2).
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of the filing date of
U.S. provisional patent application Ser. No. 62/052,884, filed on
Sep. 19, 2014, the disclosure of which is incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a non-metallic
semiconductor quantum dot and a method of carrying out a chemical
reaction or a photoluminescence reaction by using the non-metallic
semiconductor quantum dot, and in particular relates to a
non-metallic semiconductor quantum dot doped with group
III.about.VIA elements or transition elements having empty d
orbitals and a method of carrying out a chemical reaction or a
photoluminescence reaction by using the non-metallic semiconductor
quantum dot.
BACKGROUND OF THE INVENTION
[0003] The conventional metallic semiconductor quantum dots, such
as titanium dioxide (TiO.sub.2), or cadmium sulfide (CdS), can be
used for converting light energy to generate electron-hole pairs
(or redox pairs) in the light, and catalyze the reactant, such as
water, organic pollution, ammonia, etc., to perform the
oxidation-reduction reaction, and further produce hydrogen or
achieve decontamination to solve energy or environmental problems
by the different reactants. Furthermore, in the above photochemical
reaction process, the radicals or peroxides such as O.sub.2., OH.,
H.sub.2O.sub.2 are often produced, which can inhibit tumor growth
or reproduction of bacteria, and therefore can be applied to the
treatment. The electron-hole pairs generated by light can be
recombined to release photons, and carry out a photoluminescence
reaction used in detection of the target (such as a specific cell,
tissue, or microorganism) for assisting diagnosis.
[0004] The current metallic semiconductor quantum dots, such as
titanium dioxide, have disadvantages as following: (1) In the
application of photochemical reactions of solar energy, the
absorption range is ultraviolet light (wavelength less than 380 nm)
of sunlight. The absorbed energy is only 4 percent of sunlight, and
unable to effectively improve the efficiency. (2) Since the
titanium dioxide quantum dots are very stable, and not easy to
change the electronic properties by surface modification, it is not
conducive to biomedical diagnosis and treatment of specific target
design, and other applications in development related components.
(3) In the treatment, since the penetration of ultraviolet light is
very poor for skin, the UV excitation produces a low concentration
of free radicals in the human body for carrying out the
photochemical reactions. Therefore, the inhibition effect of tumor
growth or bacterial growth is very limited. (4) In the diagnosis,
titanium dioxide is a very stable quantum dot, the redox pairs
generated under the light irradiation can be stably stored in the
titanium dioxide, it is difficult to re-combine to release photons,
and therefore the target position (such as a specific cell, tissue
and microbial) cannot be effectively detected for assisting the
diagnosis.
[0005] Moreover, another general metallic semiconductor quantum
dots, such as cadmium sulfide, have disadvantages as following: (1)
In photo catalysis, although the absorption range can be extended
to infrared light (wavelength less than 700 nm), the cadmium
sulfide quantum dots are easy to be oxidized by the generated redox
pairs under light irradiation and cause photo corrosion. The
catalysis reaction cannot be performed stably. (2) In the
treatment, although the red to near-infrared light having strong
penetration can be used as a light source, however, the generation
efficiency of the free radicals or peroxides, such as O.sub.2.,
OH., H.sub.2O.sub.2, is very low, so that the treatment effect is
poor. (3) Metal cadmium has high bio-toxicity, and is not suitable
for diagnosis and treatment in vivo. (4) When applying to the
diagnosis, since the CdS quantum dots have poor hydrophilicity,
they need to perform a tedious surface modification before they can
be uniformly dispersed in water. The process complexity is
increased, the yield is declined, costs are increased, and the
stability in water phase is affected, which are against their
biomedical applications. (5) The CdS is difficult to be connected
with biological molecules (such as antibodies, proteins, nucleic
acids and lipids, etc.), resulting in a hard modification of
specificity. (6) The surface of the CdS quantum dots contains many
defects, and it is hard to carry out a photoluminescence reaction
under a light irradiation. It is necessary to design a core-shell
type composite or perform a complex surface modification to remove
the defect so as to enhance the irradiation efficiency, but the
complexity and the cost of the process are also increased.
[0006] As described above, although the conventional metallic
semiconductor quantum dots also have the ability to provide the
electron-hole pairs in the conversion of light energy to carry out
a chemical reaction or photoluminescence reaction, however, the
material properties, absorbance capacity, energy conversion
efficiency, toxicity, chemical modification of the conventional
metallic semiconductor quantum have the congenital obstacles which
are insurmountable, therefore its scope of application is
limited.
[0007] It is therefore necessary to provide a non-metallic
semiconductor quantum dot and a method of carrying out a chemical
reaction or a photoluminescence reaction by using the non-metallic
semiconductor quantum dot, in order to solve the problems existing
in the conventional technology as described above.
SUMMARY OF THE INVENTION
[0008] A primary object of the present invention is to provide a
non-metallic semiconductor quantum dot and a method of carrying out
a chemical reaction or a photoluminescence reaction by using the
non-metallic semiconductor quantum dot. The non-metallic
semiconductor quantum dot has a substrate without any metal element
itself, and has the electronic structure capable of being modified
by adjusting the size to have light absorption from ultraviolet to
infrared (wavelength greater than 200 nm and less than 1400 nm) and
generate a large number of electron-hole pairs, so as to provide
more driving force for performing a redox reaction. Moreover, when
providing energy for a long time, the corrosion is not easy to
occur, and thus the electron-hole pairs can be provided stably for
the redox reaction or the photoluminescence reaction. In addition,
compared with the traditional metallic semiconductor quantum dot,
the non-metallic semiconductor quantum dot has better
bio-compatibility due to the included elements, and has lower
bio-toxicity after surface modification or doping with non-metallic
elements. Therefore, the non-metallic semiconductor quantum dot is
more secure for organisms (especially human). On the other hand,
when the non-metallic semiconductor quantum dot is not used in
vivo, or used in some special applications in vivo, the doped
transition elements having empty d orbitals can provide a stronger
chemical reaction or photoluminescence reaction, or have additional
functions. This non-metallic semiconductor quantum dot is a
multi-functional platform having extremely high flexibility to be
suitable for use in biomedical or non-biomedical applications.
[0009] To achieve the above object, the present invention provides
a non-metallic semiconductor quantum dot, comprising a non-metallic
substrate, and having a particle size ranged from 0.3 nm to 100
nm.
[0010] In one embodiment of the present invention, the non-metallic
substrate is made of a group IVA element.
[0011] In one embodiment of the present invention, the non-metallic
substrate is a carbon-based material or a silicon-based
material.
[0012] In one embodiment of the present invention, the carbon-based
material is graphene or graphene oxide.
[0013] In one embodiment of the present invention, the non-metallic
semiconductor quantum dot comprises at least one dopant.
[0014] In one embodiment of the present invention, the dopant is
selected from at least one of group IIIA element, group IVA
element, group VA element, group VIA element, and transition
element having an empty d orbital.
[0015] In one embodiment of the present invention, the dopant is O,
N, P, B, Fe, Co, or Ni.
[0016] In one embodiment of the present invention, the dopant has a
doping ratio more than 0 mol % and less than 50 mol %.
[0017] In one embodiment of the present invention, the non-metallic
semiconductor quantum dot is disc-shaped, and has a thickness
ranged from 0.1 nm to 10 nm.
[0018] In one embodiment of the present invention, the surface of
the non-metallic substrate has at least one functional group
selected from H, a group-VA-element functional group, or a
group-VIA-element functional group.
[0019] In one embodiment of the present invention, the
group-VA-element functional group is an amino group, P, or a
phosphate group.
[0020] In one embodiment of the present invention, the
group-VIA-element functional group is hydroxyl, carbonyl, carboxyl,
or acyl.
[0021] In one embodiment of the present invention, the non-metallic
semiconductor quantum dot generates electron-hole pairs or redox
pairs by receiving a predetermined energy, so as to catalyze a
redox reaction, or to release photons by combining the
electron-hole pairs to perform a photoluminescence reaction.
[0022] In one embodiment of the present invention, the
predetermined energy is electromagnetic energy, light, electricity,
heat, magnetic energy or ultrasound.
[0023] In one embodiment of the present invention, the
photoluminescence reaction releases a light having a wavelength
ranged from 250 nm to 1600 nm.
[0024] Furthermore, the present invention provides a method of
carrying out a chemical reaction by using a non-metallic
semiconductor quantum dot, comprising steps of (1) mixing a target
sample with the abovementioned non-metallic semiconductor quantum
dot; and (2) providing the non-metallic semiconductor quantum dot
with a predetermined energy, so that the non-metallic semiconductor
quantum dot generates electron-hole pairs, and a redox reaction of
the target sample is carried out by the electron-hole pairs; or the
target sample or a surrounding molecule thereof generates an active
substance, and a redox reaction of the target sample is carried out
by the active substance.
[0025] In one embodiment of the present invention, the
predetermined energy is provided by a laser, a mercury lamp, a
visible light, an ultraviolet light, an infrared light, an
endoscopic light, an X-ray, an ultrasound, an electric field, a
magnetic field, a nuclear magnetic resonance, or a light-emitting
diode in the step (2).
[0026] In one embodiment of the present invention, the redox
reaction in the step (2) comprises decomposition of the target
sample, polymerization of the target sample, activation of the
target sample, or deactivation of the target sample.
[0027] In one embodiment of the present invention, the active
substance is a free radical or a peroxide.
[0028] In one embodiment of the present invention, the free radical
is O.sub.2. or OH.; and the peroxide is H.sub.2O.sub.2.
[0029] In one embodiment of the present invention, the target
sample is selected from biological cells, bacteria, viruses,
parasites, cell secretions, biological molecules, an organic
compound, or an inorganic compound.
[0030] In one embodiment of the present invention, the organic
compound is an aromatic compound, alcohol, aldehyde, ketone, acid,
amine, urea, or a polymer thereof.
[0031] In one embodiment of the present invention, the inorganic
compound is water, nitrite, nitrate or ammonia.
[0032] In one embodiment of the present invention, the biological
molecules are peptides, nucleic acids, lipids, carbohydrates,
vitamins, hormones, or a polymer thereof.
[0033] In one embodiment of the present invention, the cell
secretions are extracellular vesicles or extracellular matrix.
[0034] Furthermore, the present invention provides a method of
carrying out a photoluminescence reaction by using a non-metallic
semiconductor quantum dot, comprising steps of (1) delivering the
abovementioned non-metallic semiconductor quantum dot to a
predetermined position; and (2) providing the non-metallic
semiconductor quantum dot with a predetermined energy, so that the
non-metallic semiconductor quantum dot generates electron-hole
pairs, and releases photons by combining the electron-hole pairs to
perform the photoluminescence reaction.
[0035] In one embodiment of the present invention, the
predetermined energy is provided by a laser, a mercury lamp, a
visible light, an ultraviolet light, an infrared light, an
endoscopic light, an X-ray, an ultrasound, an electric field, a
magnetic field, a nuclear magnetic resonance, or a light-emitting
diode in the step (2).
[0036] In one embodiment of the present invention, the
photoluminescence reaction has a wavelength ranged from 250 nm to
1600 nm.
[0037] In one embodiment of the present invention, the method
comprises a step (3) of using the photoluminescence reaction as
being a signal source after the step (2).
DESCRIPTION OF THE DRAWINGS
[0038] FIGS. 1a to 1b show the photoluminescence reaction having
different colors generated by the amino-nitrogen-doped graphene
oxide quantum dots after irradiating with UV light according to the
Embodiment 3-2 of the present invention.
[0039] FIG. 2 is a diagram showing the concentration of the free
radical of H.sub.2O.sub.2 generated from water under different
doses in clinical cancer treatment, which is used for comparing
with the free radical of H.sub.2O.sub.2 generated by using the
non-metallic semiconductor quantum dot.
[0040] FIG. 3 shows the concentration of the free radical generated
by irradiating the nitrogen-doped graphene oxide quantum dot
according to the Embodiment 2-1 of the present invention under a
visible light.
[0041] FIGS. 4a to 4f are images of the photoluminescence reaction
of the amino-nitrogen-doped graphene oxide quantum dot of the
Embodiment 3-2 in lung cancer cells observed with multiphoton
fluorescence microscope.
[0042] FIGS. 5a to 5j show fluorescence intensity changes of the
lung cancer cells labeled by the amino-nitrogen-doped graphene
oxide quantum dots (NH.sub.2-NGOQD) of the Embodiment 3-1 and the
traditional fluorescence dyes (CellVue dye) before exciting and
after continuously exciting for 30, 60, 90 mins with a blue light
source.
[0043] FIG. 6 shows the viability of the cells treated in the
concentration of 50 mg/L with the nitrogen-doped graphene oxide
quantum dots (NGOQD) of the Embodiment 2-1 or the
amino-nitrogen-doped graphene oxide quantum dots (NH.sub.2-NGOQD)
of the Embodiment 3-1 for 72 hours.
[0044] FIGS. 7a to 7e show the generation efficiency of hydrogen
gas from decomposing ammonia (NH.sub.3) by the
boron-and-nitrogen-doped graphene oxide quantum dots (N-BGOQD:
FIGS. 7a to 7c) prepared by different process according to the
Embodiment 2-4 of the present invention, and the boron-doped
graphene oxide quantum dots (BGOQD: FIG. 7d) according to the
Embodiment 2-2 of the present invention providing with UV energy
(FIG. 7e).
[0045] FIG. 8 shows the cell labeled by the non-metallic
semiconductor quantum dot conjugated antibody (conjugating via the
functional groups on the non-metallic semiconductor quantum
dot).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0046] The structure and the technical means adopted by the present
invention to achieve the above and other objects can be best
understood by referring to the following detailed description of
the preferred embodiments. In addition, directional terms described
by the present invention, such as upper, lower, front, back, left,
right, inner, outer, side, etc., are only directions by referring
to the accompanying drawings, and thus the directional terms are
used to describe and understand the present invention, but the
present invention is not limited thereto. Furthermore, if there is
no specific description in the invention, singular terms such as
"a", "one", and "the" include the plural number. For example, "a
compound" or "at least one compound" may include a plurality of
compounds, and the mixtures thereof. If there is no specific
description in the invention, the "%" means "weight percentage (wt
%)", and the numerical range (e.g. 10%.about.11% of A) contains the
upper and lower limit (i.e. 10.ltoreq.A.ltoreq.11%). If the lower
limit is not defined in the range (e.g. less than, or below 0.2% of
B), it means that the lower limit is 0 (i.e.
0.ltoreq.B.ltoreq.0.2%). The proportion of "weight percent" of each
component can be replaced by the proportion of "weight portion"
thereof. The abovementioned terms are used to describe and
understand the present invention, but the present invention is not
limited thereto.
[0047] The present invention provides a non-metallic semiconductor
quantum dot, comprising a non-metallic substrate, and having a
particle size ranged from 0.3 nm to 100 nm, such as 0.5, 1, 5, 15,
or 50 nm, but it is not limited thereto. The non-metallic substrate
can be made of a group IVA element, such as a carbon-based material
or a silicon-based material. Preferably, the carbon-based material
is graphene or graphene oxide. Additionally, the shape of the
non-metallic semiconductor quantum dot is substantially determined
by the shape of the non-metallic substrate, which generally
presents a ball-shaped structure, but the other shape such as
pillar-shaped or disc-shaped is possible. Preferably, when the
non-metallic substrate is graphene oxide, the non-metallic
semiconductor quantum dot presents a disc-shaped structure having a
thickness ranged from 0.1 nm to 10 nm, such as 0.5, 5, or 10 nm,
but it is not limited thereto.
[0048] Furthermore, the non-metallic semiconductor quantum dot can
be provided with at least one dopant or doping atom at the same
time, for example group IIIA, IVA, VA, VIA elements, or transition
elements with empty d orbital in the periodic table. The dopant can
be O, N, P, B, Fe, Co, or Ni, etc. The ratio of the dopant to the
non-metallic substrate is less than 50 mol %, such as 10, 20, 30,
or 40 mol %, but it is not limited thereto. In addition to the
dopant, the surface of the non-metallic substrate can be modified
to attach at least one functional group for various applications.
The functional group can be selected from hydrogen atom, a
group-VA-element functional group, or a group-VIA-element
functional group, wherein the group-VA-element functional group can
be an amino group (--NH.sub.2), P, or a phosphate group
(HOPO(OR).sub.2); the group-VIA-element functional group can be
hydroxyl (--OH), carbonyl (--C.dbd.O), carboxyl (--COOH), or acyl.
Through the functional group, the non-metallic semiconductor
quantum dot and biomolecules can be bound more easily (e.g. binding
to antibodies through the amino groups) for assisting inspection,
indicating positions, image diagnosis, or cancer treatment. After
doping, the electronic and structural properties of the
non-metallic substrate can be efficiently changed, so that the
non-metallic semiconductor quantum dot can absorb a light from
visible light to infrared light (wavelength less than 1600 nm), and
the light emission rate can also be promoted to more than 70% (by
doping with N and surface modification with NH.sub.2).
[0049] Another embodiment of the present invention provides a
method of carrying out a chemical reaction by using a non-metallic
semiconductor quantum dot, mainly comprising steps of: (S1) mixing
a target sample with the abovementioned non-metallic semiconductor
quantum dot; and (S2) providing the non-metallic semiconductor
quantum dot with a predetermined energy, so that the non-metallic
semiconductor quantum dot generates electron-hole pairs, and a
redox reaction of the target sample is carried out by the
electron-hole pairs; or, the target sample or a surrounding
molecule thereof generates an active substance to carry out a redox
reaction of the target sample by the active substance. The
principle and the implementation details of each step in this
embodiment of the present invention will be described in detail
hereinafter.
[0050] First, the method of carrying out a chemical reaction by
using a non-metallic semiconductor quantum dot according to one
embodiment of the present invention is the step (S1): mixing a
target sample with the abovementioned non-metallic semiconductor
quantum dot. In this step, the way of mixing can be determined by
the type of the target sample, for example, the non-metallic
semiconductor quantum dot and the target sample can be uniformly
dispersed in a medium (e.g. water, saline solution, ethanol, etc.),
or the non-metallic semiconductor quantum dot is dispersed in the
medium firstly, and then the non-metallic semiconductor quantum dot
is introduced together with the medium to the position of the
target sample.
[0051] Next, the method of carrying out a chemical reaction by
using a non-metallic semiconductor quantum dot according to one
embodiment of the present invention is the step (S2): providing the
non-metallic semiconductor quantum dot with a predetermined energy,
so that the non-metallic semiconductor quantum dot generates
electron-hole pairs, and a redox reaction of the target sample is
directly carried out by the electron-hole pairs; or, the target
sample or a surrounding molecule thereof generates an active
substance to carry out a redox reaction of the target sample. In
this step, the target sample can be selected from biological cells,
bacteria, viruses, parasites, cell secretions, biological
molecules, an organic compound, or an inorganic compound.
Preferably, the organic compound can be an aromatic compound,
alcohol, aldehyde, ketone, acid, amine, urea, or a polymer thereof;
the inorganic compound can be water, nitrite, nitrate or ammonia;
the biological molecules can be peptides, nucleic acids, lipids,
carbohydrates, vitamins, hormones, or polymers thereof; the cell
secretions can be extracellular vesicles or extracellular matrix.
Additionally, the predetermined energy is provided by a light
source or the other such as ultrasonic or a nuclear magnetic
resonance. The light source has a wavelength ranged from 200 nm to
1400 nm, such as a laser, a mercury lamp, a visible light, an
ultraviolet light, an infrared light, an endoscopic light, an
X-ray, an ultrasound, an electric field, a magnetic field, a
nuclear magnetic resonance, or a light-emitting diode. Preferably,
the predetermined energy is provided by the visible light, the
ultraviolet light, or the infrared light to directly carry out the
redox reaction of the target sample, or the target sample or the
surrounding molecule thereof generates the active substance to
carry out a redox reaction of the target sample.
[0052] Furthermore, the redox reaction in the step (2) is mainly
decomposition of the target sample, polymerization of the target
sample, activation of the target sample, or deactivation of the
target sample. The active substance is a free radical or a
peroxide, such as O.sub.2., OH., H.sub.2O.sub.2, and etc.
[0053] The other embodiment of the present invention provides a
method of carrying out a photoluminescence reaction by using a
non-metallic semiconductor quantum dot, mainly comprising steps of:
(S1) delivering the abovementioned non-metallic semiconductor
quantum dot to a predetermined position; and (S2) providing the
non-metallic semiconductor quantum dot with a predetermined energy,
so that the non-metallic semiconductor quantum dot generates
electron-hole pairs, and releases photons by combining the
electron-hole pairs to perform a photoluminescence reaction. The
photoluminescence reaction has a wavelength ranged from 250 nm to
1600 nm.
[0054] Furthermore, in one embodiment, a step of (S3) of using the
photoluminescence reaction as being a signal source can be included
after the step (S2) of the abovementioned embodiment. The signal
source can be used for distinguishing a specific status, showing a
specific pattern or images of the target sample by wavelengths,
colors, or intensity, or providing light energy directly. For
example, different biological molecules can be labeled by using
different colors of fluorescent, a quantum dot display can be used
for showing the patterns of the fluorescent, or applying to a LED
application.
[0055] To make the non-metallic semiconductor quantum dot provided
by the present invention more definite, please refer to the
experiment process described in the following.
Embodiment 1-1
Preparation of Graphene Oxide Quantum Dot
[0056] A commercially available or self-prepared graphene oxide is
oxidized in concentrated nitric acid at room temperature for 12
hours, then the mixed solution is treated with ultrasonic vibration
for 10 hours, and the resulting mixture is placed in an exhaust gas
recovery apparatus provided with a calcination furnace and calcined
at 140.degree. C. for 12 hours in order to exclude the concentrated
nitric acid (boiling point 83.degree. C.). The product is dispersed
in 40 ml of water, and then filtered through a 0.22 .mu.m
microporous membrane and 10000 rpm of centrifugation, and the
resulting black suspensions are graphene oxide quantum dots.
Embodiment 1-2
Preparation of Graphene Oxide Quantum Dot
[0057] 0.3 g graphene oxide and 0.25 g of sodium nitrate are
weighed, and poured into 15 ml of 18M concentrated sulfuric acid
solution in an ice bath. 1.5 g of potassium permanganate is added
with stirring at 20.degree. C. Then the mixture is stirred for 12
hours at 35.degree. C. to carry out the oxidation reaction. Raising
the temperature to 98.degree. C., the mixture is stirred for 15
minutes, and 50 ml of deionized water is added. Then, at room
temperature, 3 ml of 35 wt % hydrogen peroxide (H.sub.2O.sub.2) is
added and continuously stirred to terminate the reaction, and then
the ethanol precipitated product is repeatedly washed with ethanol,
and centrifuged to obtain graphene oxide quantum dots.
Embodiment 1-3
Preparation of Graphene Oxide Quantum Dot with Different Sizes
[0058] The graphene oxide quantum dots obtained from the Embodiment
1-1 or 1-2 are centrifugalized in a centrifuge tube having a series
of different pore sizes (100 KD, 30 KD, 10 KD, 5 KD, 3 KD, 2 KD)
polyethersulfone membrane. Under the centrifugal forces, the
graphene oxide quantum dots with different particle sizes can be
separated and obtained according to the different pore sizes.
Embodiment 1-4
Preparation of Graphene Oxide Quantum Dot with Different Sizes
[0059] A serious concentrations of ethanol or phosphate buffered
saline (PBS) is established by using the graphene oxide quantum
dots obtained from the Embodiment 1-1 or 1-2. The different sized
graphene oxide quantum dots are precipitated according to different
concentrations of ethanol or PBS, and then the precipitated
graphene oxide quantum dots are collected and obtained according to
the different sizes by centrifuge.
Embodiment 2-1
Preparation of Nitrogen-Doped Graphene Oxide Quantum Dot
[0060] The graphene oxide is placed into ammonia flow and calcined
at 500.degree. C. for 3 hours to synthesize nitrogen-doped graphene
oxide. Then, the nitrogen-doped graphene oxide is oxidized in
concentrated nitric acid at room temperature for 12 hours, and the
mixed solution is treated with ultrasonic vibration for 10 hours,
the resulting mixture is placed in an exhaust gas recovery
apparatus provided with a calcination furnace and calcined at
140.degree. C. for 12 hours in order to exclude the concentrated
nitric acid (boiling point 83.degree. C.). The product is dispersed
in 40 ml of water, and then filtered through a 0.22 .mu.m
microporous membrane and 10000 rpm of centrifugation, and the
resulting brown suspensions are nitrogen-doped graphene oxide
quantum dots.
Embodiment 2-2
Preparation of Boron-Doped Graphene Oxide Quantum Dot
[0061] The boric acid is dissolved in ethanol, and then the
graphene oxide is added to the mixed solution. The mixture is dried
for 12 hours at 80.degree. C., and then heated at 500.degree. C.
under argon (Ar) flow for 3 hours to synthesize boron-doped
graphene oxide. Then, the boron-doped graphene oxide is oxidized in
concentrated nitric acid at room temperature for 12 hours, and the
mixed solution is treated with ultrasonic vibration for 10 hours,
the resulting mixture is placed in an exhaust gas recovery
apparatus provided with a calcination furnace and calcined at
140.degree. C. for 12 hours in order to exclude the concentrated
nitric acid. The product is dispersed in 40 ml of water, and then
filtered through a 0.22 .mu.m microporous membrane and 10000 rpm of
centrifugation, and the resulting brown suspensions are boron-doped
graphene oxide quantum dots.
Embodiment 2-3
Preparation of Iron-Doped Graphene Oxide Quantum Dots
[0062] The iron oxide is dissolved in ethanol, and then the
graphene oxide is added to the mixed solution. The mixture is dried
for 12 hours at 80.degree. C., and then heated at 500.degree. C.
under argon (Ar) flow for 3 hours to synthesize boron-doped
graphene oxide. Then, the boron-doped graphene oxide is oxidized in
concentrated nitric acid at room temperature for 12 hours, and the
mixed solution is treated with ultrasonic vibration for 10 hours,
the resulting mixture is placed in an exhaust gas recovery
apparatus provided with a calcination furnace and calcined at
140.degree. C. for 12 hours in order to exclude the concentrated
nitric acid (boiling point 83.degree. C.). The product is dispersed
in 40 ml of water, and then filtered through a 0.22 .mu.m
microporous membrane and 10000 rpm of centrifugation, and the
resulting brown suspensions are iron-doped graphene oxide quantum
dots.
Embodiment 2-4
Preparation of Boron-and-Nitrogen-Doped Graphene Oxide Quantum
Dot
[0063] The boron-doped graphene oxide obtained from the Embodiment
2-2 is calcined at 500.degree. C. under ammonia gas flow for 3
hours to synthesize boron-and-nitrogen-doped graphene oxide. Then,
the boron-and-nitrogen-doped graphene oxide is oxidized in
concentrated nitric acid at room temperature for 12 hours, and the
mixed solution is treated with ultrasonic vibration for 10 hours,
the resulting mixture is placed in an exhaust gas recovery
apparatus provided with a calcination furnace and calcined at
140.degree. C. for 12 hours in order to exclude the concentrated
nitric acid (boiling point 83.degree. C.). The product is dispersed
in 40 ml of water, and then filtered through a 0.22 .mu.m
microporous membrane and 10000 rpm of centrifugation, and the
resulting brown suspensions are boron-and-nitrogen-doped graphene
oxide quantum dots.
Embodiment 2-5
Preparation of Nitrogen-Doped Graphene Oxide Quantum Dots with
Different Sizes
[0064] The nitrogen-doped graphene oxide quantum dots obtained from
the Embodiment 2-1 are centrifugalized in a centrifuge tube having
a series of different pore sizes (100 KD, 30 KD, 10 KD, 5 KD, 3 KD,
2 KD) polyethersulfone membrane. Under the centrifugal forces, the
nitrogen-doped graphene oxide quantum dots with different particle
sizes can be separated and obtained according to the different pore
sizes.
[0065] A serious concentrations of ethanol or phosphate buffered
saline (PBS) is established by using the nitrogen-doped graphene
oxide quantum dots obtained from the Embodiment 2-1. The different
sized graphene oxide quantum dots are precipitated according to
different concentrations of ethanol or PBS, and then the
precipitated nitrogen-doped graphene oxide quantum dots are
collected and obtained according to the different sizes by
centrifuge.
Embodiment 3-1
Preparation of Nitrogen-Doped Graphene Oxide Quantum Dot with Amino
Groups
[0066] The nitrogen-doped graphene oxide quantum dots obtained from
Embodiment 2-1 are treated at 25.degree. C. under ammonia gas flow
for 12 hours, and the nitrogen-doped graphene oxide quantum dots
with amino groups on the surface thereof (amino-nitrogen doped
graphene oxide quantum dots) can be obtained.
Embodiment 3-2
Preparation of Nitrogen-Doped Graphene Oxide Quantum Dot with Amino
Groups with Different Sizes
[0067] The amino-nitrogen-doped graphene oxide quantum dots
obtained from the Embodiment 3-1 are centrifugalized in a
centrifuge tube having a series of different pore sizes (100 KD, 30
KD, 10 KD, 5 KD, 3 KD, 2 KD) polyethersulfone membrane. Under the
centrifugal forces, the amino-nitrogen-doped graphene oxide quantum
dots with different particle sizes can be separated and obtained
according to the different pore sizes.
[0068] A serious concentrations of ethanol or phosphate buffered
saline (PBS) is established by using the amino-nitrogen-doped
graphene oxide quantum dots obtained from the Embodiment 3-1. The
different sized amino-nitrogen-doped graphene oxide quantum dots
are precipitated according to different concentrations of ethanol
or PBS, and then the precipitated amino-nitrogen-doped graphene
oxide quantum dots are collected and obtained according to the
different sizes by centrifuge.
[0069] As shown in FIGS. 1a to 1b, the amino-nitrogen-doped
graphene oxide quantum dots with different particle sizes according
to the Embodiment 3-2 perform different colors by the
photoluminescence reaction after irradiating with ultraviolet
light. Please refer to FIG. 1a, different sizes
amino-nitrogen-doped graphene oxide quantum dots (from left to
right, from small to large diameter of 10, 16, 26, 54, 61, 79
.ANG.) present the colors from light yellow to reddish-brown color
under a visible light irradiation. Refer to FIG. 1b, after
irradiating with UV irradiation with 365 nm of wavelength,
different colors from blue to red fluorescence are generated.
Embodiment 4-1
Preparation of Silicon-Based Quantum Dot
[0070] 1.14 g of silicon tetrachloride is dissolved in 300 ml of
1,2-dimethoxyethane, and the solution containing 1.95 g of sodium
sulfide in 30 ml of THF (tetrahydrofuran) is added thereto, the
mixture is stirred at 35.degree. C. for 4 hours to perform
reduction and polymerization. Then 10 ml of a hexane solution
containing 1.6M n-butyllithium is added to terminate the
polymerization reaction. The produced mixture is washed with 500 ml
of deionized water for 3 times to remove the excess salts, and the
product is in an exhaust gas recovery apparatus provided with a
calcination furnace and calcined at 140.degree. C. for 12 hours in
order to exclude the hexane (boiling point 68.degree. C.). The
product is dispersed in 40 ml of water, filtered through a 0.22
.mu.m microporous membrane and 10000 rpm of centrifugation, and the
silicon-based quantum dots can be obtained.
Embodiment 4-2
Preparation of Silicon-Based Quantum Dots with Different Sizes
[0071] The silicon-based quantum dots obtained from the Embodiment
4-1 are centrifugalized in a centrifuge tube having a series of
different pore sizes (100 KD, 30 KD, 10 KD, 5 KD, 3 KD, 2 KD)
polyethersulfone membrane. Under the centrifugal forces, the
silicon-based quantum dots with different particle sizes can be
separated and obtained according to the different pore sizes.
Embodiment 5-1
Preparation of Nitrogen-Doped Silicon-Based Quantum Dots
[0072] The silicon-based quantum dots obtained from the Embodiment
4-1 are placed into ammonia flow and calcined at 500.degree. C. for
3 hours. Then, the mixture is oxidized in concentrated nitric acid
at room temperature for 12 hours, and the mixed solution is treated
with ultrasonic vibration for 10 hours, the resulting mixture is
placed in an exhaust gas recovery apparatus provided with a
calcination furnace and calcined at 140.degree. C. for 12 hours in
order to exclude the concentrated nitric acid (boiling point
83.degree. C.). The product is dispersed in 40 ml of water, and
then filtered through a 0.22 .mu.m microporous membrane and 10000
rpm of centrifugation to obtain the nitrogen-doped silicon-based
quantum dots.
Embodiment 5-2
Preparation of Iron-Doped Silicon-Based Quantum Dots
[0073] The iron oxide is dissolved in ethanol, and then the
silicon-based quantum dots from the Embodiment 4-1 are added to the
mixed solution. The mixture is dried for 12 hours at 80.degree. C.,
and then heated at 500.degree. C. under argon (Ar) flow for 3 hours
to synthesize boron-doped graphene oxide. Then, the boron-doped
graphene oxide is oxidized in concentrated nitric acid at room
temperature for 12 hours, and the mixed solution is treated with
ultrasonic vibration for 10 hours, the resulting mixture is placed
in an exhaust gas recovery apparatus provided with a calcination
furnace and calcined at 140.degree. C. for 12 hours in order to
exclude the concentrated nitric acid (boiling point 83.degree. C.).
The product is dispersed in 40 ml of water, and then filtered
through a 0.22 .mu.m microporous membrane and 10000 rpm of
centrifugation to obtain iron-doped silicon-based quantum dots.
Embodiment 6
Preparation of Nitrogen-Doped Silicon-Based Quantum Dots with Amino
Groups
[0074] The nitrogen-doped silicon-based quantum dots obtained from
Embodiment 5-1 are treated at 25.degree. C. under ammonia gas flow
for 12 hours, and the nitrogen-doped silicon-based quantum dots
with amino groups on the surface thereof can be obtained.
[0075] The various non-metallic semiconductor quantum dot obtained
from the abovementioned embodiments can be applied to generate free
radicals to inhibit cancers. As shown in FIG. 2, showing the
concentration of free radicals generated from water by radiation at
clinically used does. It can be understood from FIG. 2 that the
higher doses is necessary for generating higher concentration of
the free radicals of H.sub.2O.sub.2 to achieve a better treatment
effect of cancers. In addition, when the used doses reach 5 Gy, the
concentration of the free radical is about 2 .mu.M. Please refer to
FIG. 3, which shows the concentration of the free radicals
generated through the nitrogen-doped graphene oxide quantum dots of
the Embodiment 2-1 under a visible light. In FIG. 3, the
nitrogen-doped graphene oxide quantum dots are irradiated under the
visible light provided by 100 W of halogen lamp for 10 mins, and
the concentration of free radicals H.sub.2O.sub.2 can be generated
to about 2 .mu.M, while the free radicals H.sub.2O.sub.2 are
generated slightly higher than the background value without using
the nitrogen-doped graphene oxide quantum dots. Moreover, from FIG.
2 and FIG. 3, it can be understood that the use of the
nitrogen-doped graphene oxide quantum dots can produce almost the
same concentration of the free radicals at 5 Gy and at low
intensity energy source (such as visible light, infrared light,
etc.), this result also indicate that the non-metallic
semiconductor quantum dots have potential in the relevant fields of
human therapeutic application or diagnostic application.
[0076] The various non-metallic semiconductor quantum dot obtained
from the abovementioned embodiments can be applied to label the
cells with different colors. FIGS. 4a to 4f show the images of the
photoluminescence reaction by using different sizes of the
amino-nitrogen-doped graphene oxide quantum dots obtained from the
Embodiment 3-2 in lung cancer cells observed with multi-photon
fluorescence microscope. After treating the lung cancer cells with
different sizes of amino-nitrogen-doped graphene oxide quantum dots
in 50 mg/L for 24 hours, the lung cancer cells is clearly observed
to be the color of red (FIG. 4a) to blue (FIG. 4f), and thus the
non-metallic semiconductor quantum dot can be used for different
color labeling of cells, which has potentials in effective
diagnosis of diseases.
[0077] As shown in FIGS. 5a to 5j, the non-metallic semiconductor
quantum dot has higher stability compared with the traditional
fluorescence dyes. FIGS. 5a and 5b, respectively shows the lung
cancer cells treated with the traditional fluorescence dye (CellVue
dye) or the amino-nitrogen-doped graphene oxide quantum dots of the
Embodiment 3-1. FIGS. 5c, 5e, 5g, and 5i respectively shows the
fluorescence signal of the lung cancer cells labeled by the
traditional fluorescence dye (CellVue dye) before excitation, and
excitation for 30, 60, 90 mins, wherein the fluorescence signal in
FIG. 5e is weakened significantly, and the fluorescence signals in
FIGS. 5g and 5i are almost disappeared. However, in FIGS. 5d, 5f,
5h, 5j, compared to the fluorescence signal before excitation (FIG.
5d), after excitation for 30, 60, 90 mins, the fluorescence signal
of the lung cancer cells labeled by the amino-nitrogen-doped
graphene oxide quantum dots of the Embodiment 3-1 are reduced
slightly (FIGS. 5f, 5h, 5j). This result shows that the
non-metallic semiconductor quantum dot has higher stability
compared with the traditional fluorescence dyes.
[0078] As shown in FIG. 6, the nitrogen-doped graphene oxide
quantum dots of the Embodiment 2-1 (NGOQD), or the
amino-nitrogen-doped graphene oxide quantum dots of the Embodiment
3-1 (NH.sub.2-NGOQD) is used in cells with a high concentration of
50 mg/L, the cell viability is not affected after cultivating for
72 hours. That shows the features of low bio-toxicity.
[0079] As shown in FIGS. 7a to 7e, the boron-and-nitrogen-doped
graphene oxide quantum dots according to the Embodiment 2-4 of the
present invention (N-BGOQD: FIGS. 7a to 7c), and the boron-doped
graphene oxide quantum dots according to the Embodiment 2-2 (BGOQD:
FIG. 7d) can decompose ammonia (NH.sub.3) efficiently and generate
hydrogen gas under an ultraviolet light (FIG. 7e). The non-metallic
semiconductor quantum dots indeed have the ability for treating the
contaminants.
[0080] A fluorescent secondary antibody is formed by connecting the
NH.sub.2 group on the amino-nitrogen-doped graphene quantum dots
from the Embodiment 3-1 and a secondary antibody of anti-mouse IgG.
The fluorescent secondary antibody is used for fitting with a
specific primary antibody of mouse anti-human .beta.-actin to
detect .beta.-actin protein expression in lung cancer cells with
fluorescence microscope. As shown in FIG. 8, the protein expression
of the .beta.-actin in the cells can be detected specifically by
the fluorescence signals, which shows that the non-metallic
semiconductor quantum dot has potentials in the application of
effective diagnosis of disease.
[0081] Compared with the traditional metal semiconductor quantum
dot, the non-metallic semiconductor quantum dot according to the
present invention can extend or shorten the absorption wavelength,
and have multi-photon reaction. In addition, the non-metallic
semiconductor quantum dot according to the present invention can
exert photochemical reaction and photoluminescence properties with
high stability, and low bio-toxicity. The non-metallic
semiconductor quantum dot is very suitable for biomedical use,
application of green energy source, and contaminant treatment. In
addition, the high efficient fluorescent with multi-colors, the
redox ability, and stability can be obtained by surface
modification (with dopant or functional group) and size
adjustment.
[0082] The present invention has been described with preferred
embodiments thereof and it is understood that many changes and
modifications to the described embodiments can be carried out
without departing from the scope and the spirit of the invention
that is intended to be limited only by the appended claims.
* * * * *