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1.
Carbohydr Polym ; 326: 121623, 2024 Feb 15.
Article in English | MEDLINE | ID: mdl-38142100

ABSTRACT

A novel cellulose nanofibril/titanate nanofiber modified with CdS quantum dots hydrogel (CTH) was synthesized as an effective, stable, and recyclable photocatalytic adsorbent using cellulose nanofibril (CN), titanate nanofiber (TN), and CdS quantum dots. Within the CTH structure, CN formed an essential framework, creating a three-dimensional (3D) porous structure that enhanced the specific surface area and provided abundant adsorption sites for Cr(VI). Simultaneously, TN modified with CdS quantum dots (TN-CdS) served as a nanoscale Z-type photocatalyst, facilitating the efficient separation of photoinduced electrons and holes, further increasing the photocatalytic efficiency. The morphological, chemical, and optical properties of CTH were thoroughly characterized. The CTH demonstrated the maximum theoretical adsorption capacity of 373.3 ± 14.2 mg/g, which was 3.4 times higher than that of CN hydrogel. Furthermore, the photocatalytic reduction rate constant of the CTH was 0.0586 ± 0.0038 min-1, which was 6.4 times higher than that of TN-CdS. Notably, CTH displayed outstanding stability, maintaining 84.9 % of its initial removal efficiency even after undergoing five consecutive adsorption-desorption cycles. The remarkable performance of CTH in Cr(VI) removal was attributed to its 3D porous structure, comprising CN and TN-CdS. These findings provide novel insights into developing a stable photocatalytic adsorbent for Cr(VI) removal.

2.
Exploration (Beijing) ; 3(5): 20230050, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37933284

ABSTRACT

Finding effective strategies to design efficient photocatalysts and decompose refractory organic compounds in wastewater is a challenging problem. Herein, by coupling element doping and constructing heterostructures, S-scheme CdS QDs/La-Bi2WO6 (CS/LBWO) photocatalysts are designed and synthesized by a simple hydrothermal method. As a result, the RhB degradation efficiency of the optimized 5% CS/LBWO reached 99% within 70 min of illumination with excellent stability and recyclability. CS/LBWO shows improvement in the adsorption range of visible light and promotes electron-hole pair generation/migration/separation, attributing the superior degradation performance. The degradation RhB mechanism is proposed by a free radical capture experiment, electron paramagnetic resonance, and high-performance liquid chromatography-mass spectrometry results, indicating that h+ and •O2 - play a significant role during four degradation processes: de-ethylation, chromophore cleavage, ring opening, and mineralization. Based on in situ irradiated X-ray photoelectron spectroscopy, Mulliken electronegativity theory, and the work function results, the S-scheme heterojunction of CS/LBWO promotes the transfer of photogenerated electron-hole pairs and promotes the generation of reactive radicals. This work not only reports that 5% CS/LBWO is a promising photocatalyst for degradation experiments but also provides an approach to design advanced photocatalysts by coupling element doping and constructing heterostructures.

3.
Mikrochim Acta ; 190(8): 304, 2023 07 19.
Article in English | MEDLINE | ID: mdl-37466700

ABSTRACT

A novel electrochemiluminescence (ECL) aptasensor, using graphite carbonitride (g-C3N4) capped CdS quantum dots (CdS QDs@g-C3N4) and Au nanoparticles decorated triethanolamine (AuNPs@TEOA) as dual coreactants, was proposed for the determination of mucin 1 (MUC1). Higher ECL efficiency was acquired due to the double enhancement contribution of CdS QDs and TEOA to Ru (bpy)32+ ECL. Additionally, AuNPs@TEOA also acted as nanocarrier for MUC1 aptamer immobilization. After the aptasensor was incubated in target MUC1, the decreased ECL emission was obtained because of the poor conductivity of MUC1. The ECL aptasensor displayed a good linear correlation for MUC1 in the range 0.1 pg mL-1 -1000 ng mL-1, and the detection limit was 33 fg mL-1. MUC1 spiked into human serum samples was quantified to assess the practicability of the ECL aptasensor.


Subject(s)
Gold , Metal Nanoparticles , Humans , Mucin-1 , Electrochemical Techniques , Luminescent Measurements
4.
Arch Microbiol ; 205(7): 259, 2023 Jun 08.
Article in English | MEDLINE | ID: mdl-37289260

ABSTRACT

The potential of CdS quantum dots for biomedical and bioimaging applications depends on their cytotoxicity, which can be modulated by coating molecules. Using sulfur as a precursor can be used along with cadmium nitrate to synthesize CdS quantum dots with the fungus Fusarium oxysporum f. sp. lycopersici. The latter replaces pure chemical sulfur as a precursor for CdS quantum dot synthesis, thus transforming waste into a value-added product, increasing sustainability, reducing the environmental impact of the process through the implementation of green synthesis techniques, and contributing to the circular economy. Therefore, we compared the cytotoxicity on HT-29 cells of biogenic, and chemical CdSQDs, synthesized by a chemical method using pure sulfur. Biogenic and chemical CdSQDs had diameters of 4.08 ± 0.07 nm and 3.2 ± 0.20 nm, Cd/S molar ratio of 43.1 and 1.1, Z-potential of - 14.77 ± 0.64 mV and - 5.52 ± 1.11 mV, and hydrodynamic diameters of 193.94 ± 3.71 nm and 152.23 ± 2.31 nm, respectively. The cell viability improved 1.61 times for biogenic CdSQDs over chemical CdSQDs, while cytotoxicity, measured as IC50, diminished 1.88-times. The lower cytotoxicity of biogenic CdSQDs was attributed to their organic coating consisting of lipids, amino acids, proteins, and nitrate groups that interacted with CdS through -OH and -SH groups. Therefore, the biogenic synthesis of CdSQDs has repurposed a pathogenic fungus, taking advantage of the biomolecules it secretes, to transform hazardous sulfur waste and metal ions into stable CdSQDs with advantageous structural and cytotoxic properties for their potential application in biomedicine and bioimaging.


Subject(s)
Fusarium , Quantum Dots , Quantum Dots/toxicity , Quantum Dots/chemistry , Fungi , Sulfur
5.
Anal Chim Acta ; 1226: 340265, 2022 Sep 15.
Article in English | MEDLINE | ID: mdl-36068063

ABSTRACT

Herein, a high-sensitivity photoelectrochemical (PEC) biosensor was developed based on CdS quantum dots (QDs) sensitized porous hexagonal boron nitride (h-BN) nanosheets (NSs) and the multiple sites tripodal DNA walker (TDW) formed by catalytic hairpin assembly (CHA). Noticeably, the porous structure of h-BN NSs gives it a lasting gift of large specific surface areas and extensive active reaction sites, which makes it possible to be employed as photoelectric substrate material. The h-BN/CdS QDs composite material promotes the transmission of photogenerated electrons and holes, the outstanding photoelectric conversion efficiency. Meanwhile, the CHA-formed TDWs triggered by miRNA-141 moved on track strand-functionalized electrode, so that a large number of alkaline phosphatase (ALP) was immobilized on the electrode surface and further in situ catalyzed ascorbic acid 2-phosphate (AAP) to produce ascorbic acid (AA) as the electron donor. As the result of the decisive influence of electron donor on PEC biosensor, the sensitive detection of miRNA-141 was realized. The proposed PEC biosensor displayed an excellent linear relationship ranging from 1 fM to 100 nM with a detection limit of 0.73 fM, providing a powerful strategy for early clinical diagnosis and biomedical research.


Subject(s)
Biosensing Techniques , Cadmium Compounds , MicroRNAs , Quantum Dots , Boron Compounds , Cadmium Compounds/chemistry , DNA/genetics , Electrochemical Techniques , Limit of Detection , Quantum Dots/chemistry
6.
Food Chem ; 390: 133116, 2022 Oct 01.
Article in English | MEDLINE | ID: mdl-35569396

ABSTRACT

A new yellow CdS quantum dots (CdS QDs) with 59% quantum yield were synthesized successfully by one-pot method using thioglycolic acid as stabilizer, thiourea and sodium sulfide as double reducing agents. Based on CdS QDs, a novel "on-off" sensor for detecting Cu2+, Hg2+ and Mg2+ in foods has been constructed in the presence of glutathione (GSH). The fluorescence intensity of CdS QDs is improved about 1.5-fold by GSH, then quenched linearly by Cu2+, Hg2+ and Mg2+ owning to the electron transfer or ligand competition. Interestingly, without GSH, CdS QDs has no fluorescence response to Hg2+ at all, and with GSH, linear ranges of Cu2+ and Mg2+ is not only broader, but sensitivities are improved 16.9-fold for Cu2+ and 8.5-fold for Mg2+. GSH-CdS QDs sensor discloses a more sensitive, efficient and selective methodology for monitoring Cu2+, Hg2+ and Mg2+ in further heavy metal pollution and food safety.


Subject(s)
Cadmium Compounds , Mercury , Quantum Dots , Glutathione , Spectrometry, Fluorescence/methods
7.
Molecules ; 27(7)2022 Mar 24.
Article in English | MEDLINE | ID: mdl-35408497

ABSTRACT

An ascorbic acid (AA) sensor was constructed based on the fluorescence resonance energy transfer (FRET) between CdS quantum dots (CdS QDs) and polydopamine (PDA) to detect trace AA sensitively. FRET occurred due to the broad absorption spectrum of PDA completely overlapped with the narrow emission spectrum of CdS QDs. The fluorescence of CdS QDs was quenched and in the "off" state. When AA was present, the conversion of DA to PDA was hindered and the FRET disappeared, resulting in the fluorescence of CdS QDs in an "on" state. Importantly, the degree of fluorescence recovery of CdS QDs displayed a desirable linear correlation with the concentration of AA in the range of 5.0-100.0 µmol/L, the linear equation is y=0.0119cAA+0.3113, and the detection limit is 1.16 µmol/L (S/N = 3, n = 9). There was almost no interference with common amino acid, glucose and biological sulfhydryl small molecules to AA. Trace amount of AA in vitamin C tablets were determined and satisfactory results were obtained; the recoveries were observed to be 98.01-100.7%.


Subject(s)
Quantum Dots , Ascorbic Acid/chemistry , Fluorescence , Fluorescence Resonance Energy Transfer , Indoles , Limit of Detection , Polymers , Quantum Dots/chemistry
8.
J Fluoresc ; 32(3): 1099-1107, 2022 May.
Article in English | MEDLINE | ID: mdl-35305208

ABSTRACT

A new hybrid fluorescent nanosensor (Flu@Mea-CdS) for the Cu2+ detection in aqueous solution was constructed through fluorescence resonance energy transfer (FRET). The Flu@Mea-CdS was fabricated by amide linkage between CdS quantum dots capped with cysteamine (Mea-CdS) and fluorescein. With the formation of FRET process from Mea-CdS quantum dots to fluorescein, the fluorescence intensity of fluorescein at 520 nm was significantly enhanced. In addition, the sensor based on FRET has high selectivity for Cu2+ ions detection. With the presence of Cu2+ ions, Cu2+ ions were transferred to Cu2S by the reaction with Flu@Mea-CdS, which caused the inhibition of FRET process and quenched the fluorescence signal of 520 nm. Compared with Mea-CdS quantum dots, the Flu@Mea-CdS sensor has a lower detection limit for Cu2+. The linear range is 4-14 µM, and the detection limit is 0.17 µM. The sensor has been successfully applied to the detection of Cu2+ ions in practical samples, which shows its potential application value in environmental monitoring.


Subject(s)
Quantum Dots , Carbon , Copper , Fluorescein , Fluorescence Resonance Energy Transfer , Fluorescent Dyes , Ions , Spectrometry, Fluorescence
9.
Chemosphere ; 287(Pt 1): 131994, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34478969

ABSTRACT

In this work, a CdSe@CdS quantum dots (QDs) based label-free electrochemiluminescence (ECL) aptasensor was developed for the specific and sensitive detection of ochratoxin A (OTA). Chitosan (CHI) could immobilize abundant QDs on the surface of an Au electrode as the luminescent nanomaterials. Glutaraldehyde was used as the crosslinking agent for coupling a large number of OTA aptamers. Thanks to the excellent stability, good biocompatibility, and strong ECL intensity of CdSe@CdS QDs, as well as the quick reactions of the generated SO4•- in the electrolyte, strong ECL signals were measured. Because of the specific recognition of aptamer toward OTA, the reduced ECL signals caused by OTA in the samples were recorded for quantify the content of OTA. After optimizing a series of crucial conditions, the ECL aptasensor displayed superior sensitivity for OTA with a detection limit of 0.89 ng/mL and a wide linear concentration range of 1-100 ng/mL. The practicability and viability were verified through the rapid and facile analysis of OTA in real Lily and Rhubarb samples with recovery rates (n = 3) of 98.1-105.6% and 97.3-101.5%, respectively. The newly-developed QDs-based ECL aptasensor provided a new universal analytical tool for more mycotoxins in safety assessment of foods and feeds, environmental monitoring, and clinical diagnostics.


Subject(s)
Biosensing Techniques , Cadmium Compounds , Quantum Dots , Selenium Compounds , Electrochemical Techniques , Luminescent Measurements , Ochratoxins
10.
J Fluoresc ; 31(6): 1805-1813, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34519934

ABSTRACT

This work focuses on the synthesis of novel modified core-shell CdTe/CdS quantum dots (QDs) and develops as a fluorescence sensor for glucose determination. The (E)-2,2'-(4,4'-dioxo-2,2'-dithioxo-2H,2'H-[5,5'-bithiazolylidene]-3,3'(4H,4'H)-diyl)bis(3- mercaptopropanoic acid) (DTM) as a new derivative of thiazolidine was synthesized and characterized and used to surface-modification of CdTe/CdS QDs. DTM-capped CdTe/CdS QDs used to immobilization of glucose oxidase (GOD). The intensity fluorescence emission of the CdSe/CdS-DTM/GOD is highly sensitive to the concentration of H2O2 as a byproduct of the catalytic oxidation of glucose. The experimental results showed that the quenched fluorescence was proportional to the glucose concentration within the range of 10 nM-0.32 µM under optimized experimental conditions. The limit of detection of this system was found to be 4.3 nM. Compared with most of the existing methods, this newly developed system possesses many advantages, including simplicity, low cost, and good sensitivity.


Subject(s)
Biocompatible Materials/chemistry , Fluorescent Dyes/chemistry , Glucose Oxidase/chemistry , Glucose/analysis , Quantum Dots/chemistry , Thiazolidines/chemistry , Biocompatible Materials/metabolism , Cadmium Compounds/chemistry , Cadmium Compounds/metabolism , Colloids/chemistry , Enzymes, Immobilized/chemistry , Enzymes, Immobilized/metabolism , Fluorescent Dyes/metabolism , Glucose/metabolism , Glucose Oxidase/metabolism , Molecular Structure , Quantum Dots/metabolism , Sulfides/chemistry , Sulfides/metabolism , Surface Properties , Tellurium/chemistry , Tellurium/metabolism , Thiazolidines/metabolism
11.
J Colloid Interface Sci ; 601: 186-195, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34077841

ABSTRACT

For the first time, CdS quantum dots (QDs)-decorated InOOH (CdS-In for short) was synthesized by a facile photodeposition method. The experiment results showed that CdS-In samples exhibited excellent activity and stability towards photocatalytic reduction of nitro aromatics. The conversion ratio of 4-nitroaniline (4-NA) over CdS-In sample that was prepared with photodeposition time of 120 min (CdS-In-120) reached up to 99.4% under visible light irradiation for 40 min, which was even higher than that achieved over commercial CdS (86.2%). Besides the significant enhancement of visible light absorption, quantum sized CdS were decorated evenly on the surface of InOOH, which was very beneficial for the high activity. Furthermore, the heterogeneous junction formed at the interface of CdS QDs and InOOH can significantly increase the separation efficiency of photogenerated charge carriers. Active species control experiment and electron spin resonance (ESR) technique have proved that photogenerated electrons are the main active species towards photocatalytic reduction of nitro aromatics. It is anticipated that our study would offer meaningful insights for exploring novel InOOH-based visible light photocatalysts towards efficient reduction of nitro aromatics.


Subject(s)
Quantum Dots , Catalysis , Light
12.
Article in English | MEDLINE | ID: mdl-33760710

ABSTRACT

There is currently controversy over the use of quantum dots (QDs) in biological applications due to their toxic effects. Therefore, the purpose of the present study was to evaluate the toxic effect of chemical and biogenic (synthesized by Fusarium oxysporum f. sp. lycopersici) cadmium sulfide quantum dots (CdSQDs) using a bacterial model of Escherichia coli and sprouts of Lactuca sativa L. with the aim to foresee its use in the near future in biological systems. Physicochemical properties of both types of CdSQDs were determined by TEM, XRD, zeta potential and fluorescence spectroscopy. Both biogenic and chemical CdSQDs showed agglomerates of spherical CdSQDs with diameters of 4.14 nm and 3.2 nm, respectively. The fluorescence analysis showed a band around 361 nm in both CdSQDs, the zeta potential was -1.81 mV for the biogenic CdSQDs and -5.85 mv for the chemical CdSQDs. Results showed that chemical CdSQDs, presented inhibition in the proliferation of E. coli cell in a dose-dependent manner, unlike biogenic CdSQDs, that only at its highest concentration showed an antibacterial activity. Also, it was observed that after incubation with chemical and biogenic CdSQDs of L. sativa L. seeds, only the biogenic CdSQDs showed no inhibition on seed germination. In summary, our results suggest that the production route has a significant effect on the toxicity of QDs; in addition, it seems that the biological coating of the CdSQDs from F. oxysporum f. sp. lycopersici inhibit their toxic effect on bacterial strains and plant seeds.


Subject(s)
Cadmium Compounds/metabolism , Fusarium/metabolism , Lactuca/drug effects , Quantum Dots/chemistry , Quantum Dots/toxicity , Seeds/drug effects , Sulfides/metabolism , Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Cadmium Compounds/chemistry , Escherichia coli/drug effects , Spectrometry, Fluorescence , Sulfides/chemistry
13.
Talanta ; 225: 121964, 2021 Apr 01.
Article in English | MEDLINE | ID: mdl-33592718

ABSTRACT

A label-free ratiometric electrochemiluminescence (ECL) sensing strategy for the sensitive detection of target DNA (T-DNA) was proposed on the basis of G-quadruplex/hemin-regulated ECL emissions of CdS quantum dots (QDs) and luminol with their common coreactant of H2O2. The ECL biosensor was constructed through stepwise assemblies of CdS QDs and hairpin DNA (H-DNA) on a glassy carbon electrode, and subsequent introduction of T-DNA resulted in the development of G-quadruplex/hemin DNAzymes via the specific recognition of T-DNA and H-DNA in the presence of hemin and K+ ions. The formed DNAzymes not only prompted the catalytic oxidation of hydroquinone followed by deposition of insoluble oxidation oligomers on the electrode surface to attenuate the cathodic ECL emission of CdS QDs but also triggered the catalytic oxidation of luminol to enhance the anodic ECL emission. The label-free ratiometric ECL biosensor for the detection of T-DNA showed a wide response range from 1 to 10,000 fM (10-15 M) with a low detection limit of 0.2 fM and exhibited excellent selectivity against mismatched base sequences. This work provides a reliable and sensitive sensing platform for the detection of targets in analytical community by means of rational design of DNA sequences.


Subject(s)
Biosensing Techniques , DNA, Catalytic , Quantum Dots , DNA , Hydrogen Peroxide , Luminescent Measurements
14.
Chemosphere ; 277: 128730, 2021 Aug.
Article in English | MEDLINE | ID: mdl-33189399

ABSTRACT

Visible-light-driven photocatalysis is a green and efficient strategy for wastewater treatment, where graphitic carbon nitride-based semiconductors showed excellent performance in this regard. Consequently, we report on the development of a green and facile one-pot room-temperature ultrasonic route for the preparation of novel ternary nanocomposite of cadmium sulfide quantum dots (CdS QDs), zinc oxide nanoparticles (ZnO NPs), and graphitic carbon nitride nanosheets (g-C3N4 NSs). The proposed materials had been characterized by several physicochemical techniques such as PXRD, XPS, FE-SEM, HR-TEM, PL, and DRS. The photocatalytic efficiency of the proposed photocatalysts was assessed towards the photodegradation of Rhodamine B dye as a water pollutant model using spectrophotometric measurements. The as-synthesized novel ternary nanocomposite (CdS@ZnO/g-C3N4) exhibited perfect photocatalytic activity, where almost complete degradation was achieved in only 2 h under UV-irradiation or 3 h under visible-irradiation. Various methods were used to elucidate the kinetics of the photocatalytic process. Moreover, CdS@ZnO/g-C3N4 exhibited a unique synergetic performance when compared to the corresponding binary composites or the individual components. This synergetic performance could be ascribed to the perfect electronic band configuration of the three components, leading to the establishment of several combined synergetic Z-Scheme/Type-II photocatalytic heterojunctions, which is the proposed mechanism for the observed synergetic photocatalytic reactivity of the as-synthesized CdS@ZnO/g-C3N4 nanocomposite when compared to the single and binary nanocomposite counterparts. Furthermore, the effects of both the type and concentration of various scavengers on the photocatalytic activity were assessed to investigate the most reactive species, where the reductive degradation pathway was found to be the predominant route. Finally, the photocatalytic efficiency of the as-synthesized CdS@ZnO/g-C3N4 composite showed promising and competing results when compared to other photocatalysts reported in the literature.


Subject(s)
Nanocomposites , Zinc Oxide , Catalysis , Kinetics , Photolysis
15.
Turk J Chem ; 45(6): 1952-1958, 2021.
Article in English | MEDLINE | ID: mdl-38144599

ABSTRACT

In this study, colloidal CdS quantum dots were synthesized, structurally characterized, and their effect on performance of perovskite solar cells was observed by using them as interface modification agent between TiO2/perovskite. Colloidal CdS quantum dots were synthesized based on two-phase method and characterized by X-ray diffraction and Transmission Electron Microscopy techniques. The average particle size of CdS quantum dots have found to be around 5 nm. Oleic acid was used as capping agent during synthesis to lead solubility in organic solvents. Obtained quantum dots are coated on compact TiO2 layer for surface modification. A decrease was observed when oleic acid capped CdS quantum dots were used at interface, while significant improvement was observed when ligand exchange was carried out by pyridine before perovskite layer. Reference solar cells showed 11.6% efficiency, while pyridine capped CdS modified solar cells' efficiency was 13.2%. Besides the improvement in efficiency, reproducibility of solar cells also was increased by using pyridine capped CdS as interface material.

16.
J Fluoresc ; 30(6): 1601-1609, 2020 Dec.
Article in English | MEDLINE | ID: mdl-32780264

ABSTRACT

Targeting to obtain better water solubility and stability and less aggregation-caused quenching effects of quantum dots, two kinds of thiol molecules, glutathione and L-cysteine, were firstly united to offer stabilizing ligands for aqueous synthesized CdS quantum dots, which exhibited sensitive aggregation-induced emission properties. Fluorescent intensity of the CdS quantum dots was enhanced about 5 folds by simple solvent exchange from water to 90 vol% PEG200. Restriction of intramolecular motions in an aggregate state was probably the main cause of the phenomenon. At the same time, fluorescent intensity of CdS quantum dots in the presence of zinc ions was able to be enhanced about 2.2 folds. Based on the researches, a handy metal enhanced fluorescent probe for detecting zinc ions was established. And the detection limit was 0.58 µmol/L. Zinc ions as a bridge among CdS quantum dots to form aggregates limited motions of CdS quantum dots to a certain extent and simultaneously enhanced their fluorescence emission intensities. Meanwhile, activation of surface states of CdS quantum dots also led to emission enhancement. Both of the two factors together contributed to the fluorescence enhancement and ultimately to the sensitivity to zinc ion sample detection.


Subject(s)
Cadmium Compounds/chemistry , Cysteine/chemistry , Fluorescent Dyes/chemistry , Glutathione/chemistry , Quantum Dots/chemistry , Sulfides/chemistry , Zinc/chemistry , Limit of Detection , Polyethylene Glycols/chemistry , Solubility , Solvents/chemistry , Spectrometry, Fluorescence , Zinc/analysis
17.
Small ; 16(26): e2001024, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32484310

ABSTRACT

Herein, oil-soluble CdS quantum dots (QDs) are first prepared through a solvent-thermal process. Then, oil-soluble CdS QDs are changed into water-soluble QDs via ligand exchange using mercaptopropionic acid as capping agent at pH 13. The photocatalytic performance is investigated under the visible light irradiation using glycerol as sacrificial agent and Sn2+ as cocatalyst. No H2 -production activity is observed for oil-soluble CdS QDs. Water-soluble CdS QDs exhibit significantly enhanced hydrogen evolution rate. When the concentration of cocatalyst Sn2+ increases to 0.2 × 10-3 m, the rate of hydrogen evolution reaches 1.61 mmol g-1 h-1 , which is 24 times higher than that of the pristine water-soluble CdS QDs. The enhanced H2 -production efficiency is attributed to the adsorption of Sn2+ ions on the surface of CdS QDs that are further reduced to Sn atoms by photogenerated electrons. The in situ generated Sn atoms serve as photocatalytic cocatalyst for efficient hydrogen generation.

18.
ACS Appl Mater Interfaces ; 12(26): 29066-29073, 2020 Jul 01.
Article in English | MEDLINE | ID: mdl-32510918

ABSTRACT

We report here CdS quantum-dots (QDs)-decorated V2O5 nanosheets as high-performance and chemically etchable photoelectric active materials for constructing a photoelectrochemical (PEC) immunoassay platform. CdS QDs-decorated V2O5 nanosheets as new photoelectric materials can show superior photocurrent to V2O5 nanosheets and CdS QDs under visible-light irradiation because of the promoted photogenerated electron-hole separation and the increased visible-light absorption. V2O5 nanosheets can be etched by ascorbic acid (AA) because of the reduction of V2O5 to V4+, and the photocurrent of CdS/V2O5-nanocomposite-modified indium tin oxide electrode decreases significantly after being etched by AA. Inspired by this phenomenon, a PEC immunoassay platform is constructed for carcinoembryonic antigen (CEA) detection by using CdS/V2O5 nanocomposite as the photoelectric material and AA-encapsulated liposome immunonanocapsules as labels. The linear detection range for detecting CEA is from 0.5 pg mL-1 to 1 ng mL-1, with a limit of detection of 0.1 pg mL-1. The proposed method also shows good selectivity, excellent reproducibility, and satisfactory recovery in detection of CEA in human serum samples. We believe that this work will lay the foundation for the future development of V2O5-based materials for PEC analysis, and also provide a reasonable design and implementation for the development of PEC immunoassay.


Subject(s)
Cadmium Compounds/chemistry , Carcinoembryonic Antigen/analysis , Electrochemical Techniques/methods , Immunoassay/methods , Photochemistry/methods , Quantum Dots , Ascorbic Acid/chemistry
19.
J Colloid Interface Sci ; 577: 1-11, 2020 Oct 01.
Article in English | MEDLINE | ID: mdl-32464336

ABSTRACT

CdS quantum dots (QDs) were decorated onto phosphorus-doped hexagonal g-C3N4 tube (P-CNT) to form a novel high-preformance photocatalyst (CdS QDs/P-CNT) via an in-situ oil bath approach. The ultra-small CdS QDs with the average diameter of ~9 nm are homogeneously anchored on the both external and internal surface of P-CNT hollow channel (~25 µm), yielding a type of zero-dimensional (0D)/one-dimensional (1D) heterojunction. The CdS QDs/P-CNT-1 exhibits the maximum photocatalytic H2 evolution rate of 1579 µmol h-1 g-1 under visible-light irradiation, which is 31.6, 6.8, 4.7 and 3.1 times higher than P-CNT, CdS, CdS/BCN and CdS/CNT, respectively. The improved photocatalytic activity of CdS QDs/P-CNT is primarily attributed to large surface area, P doping and formed 0D/1D heterojunction, which can broaden the light absorption, narrow the band gap, activate the H2O molecule and promote the spatial charge separation. Moreover, the DFT calculation coupled with experiment (Mott-Schottky curves) illustrates the electron transfer behavior of CdS QDs/P-CNT, showing that the Cd-1 site should be the main active center and P doping is beneficial to increase H2 production. This work provides a new strategy to design of highly active 0D/1D photocatalyst for photocatalytic H2 production.

20.
Data Brief ; 30: 105636, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32426426

ABSTRACT

The data included in this paper are associated with a research article entitled 'Differences in toxicity, mitochondrial function and miRNome in human cells exposed in vitro to Cd as CdS quantum dots or ionic Cd' [1]. The article concerns the use of miRNAs as biomarkers for engineered nanomaterials (ENMs) risk assessment. Two different type of human cells, HepG2 and THP-1, were exposed to different forms of Cadmium: nanoscale, as CdS quantum dots (CdS QDs), and ionic, as CdSO4 8/3 -hydrate (Cd(II)). The cells were treated with sub-toxic doses of CdS QDs; 3 µg ml-1 in HepG2 and 6.4 µg ml-1 and 50 µg ml-1 in THP-1, as well as equivalent cadmium doses as Cd(II). In this dataset, changes in expression levels of miRNAs are reported. In addition, GO enrichment analyses of target genes of miRNAs modulated by Cd stress, network analysis of the microRNome and an in silico pathway analysis are also reported. These data enhance and also summarize much of the data independently presented in the research article and therefore, must be considered as supplementary.

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