Journal of Physical Chemistry C
·
2015
·
IF 4.772
Junwei Yang,Jin Wang,Ke Zhao,Takuya Izuishi,Yan Li,Qing Shen,Xinhua Zhong
Surface trap defects are the limited factor for quantum dots (QDs) application in solar cells. The trapping states can be efficiently suppressed by coating a shell of wider band gap material around the core QDs. We choose CdSe0.65Te0.35 (simplified as CdSeTe) as a model core material, and CdS shell was then overcoated around the CdSeTe core QD to decrease surface defect density and to increase the stability of the core QDs. By optimizing the thickness of the CdS shell, the power conversion efficiency (PCE) of the CdSeTe/CdS quantum dots sensitized solar cells (QDSCs) is enhanced by 13% in comparison with that of plain CdSeTe QDSCs. Transient absorption (TA), incident-photo-to-carrier conversion efficiency (IPCE), open-circuit voltage decay (OVCD), and electrochemical impedance spectroscopy (EIS) measurements confirmed the suppressed charge recombination process in internal QDs and QD/TiO2/electrolyte interfaces with the overcoating of CdS shell around CdSeTe core QDs. With the further overcoating of a-TiO2 and SiO2 barrier layers around the QD-sensitized photoanode, the PCE of champion CdSeTe QDSCs achieved 9.48% (Jsc = 20.82 mA/cm2, Voc = 0.713 V, FF = 0.639) with average PCE 9.39 ± 0.09% under AM 1.5 G one full sun illumination.
研究领域:
材料科学
·
能源研究
✓ 已验证
产品关联
DOI
高影响因子
CHEMPHYSCHEM
·
2015
·Vol. 16
·期 13
·2826-2835
·
IF 3.419
Shiwei Zhou,Yingying Wang,Ming Zhao,Li-Ping Jiang,Jun-Jie Zhu
Graphical Joining the dots: A core–shell–shell CdSeTe@CdS@ZnS quantum-dot-sensitized macroporous TiO 2 plate is built as a photoelectrochemical signal output system, and the film is modified further with biotin–DEVD–peptide, which can be cleaved specifically by caspase-3 and streptavidin-labeled alkaline phosphatase (SA-ALP), to assemble a multisignal-amplified photoelectrochemical platform. A macroporous TiO 2 film (M-TiO 2 ), which was prepared by burning off the polystyrene microsphere (PS) template from a PS/TiO 2 composite film, can provide a large active surface, improve electron-transport performance, and increase the photocurrent. Furthermore, core–shell–shell CdSeTe@CdS@ZnS quantum dots (QDs) were introduced to sensitize the M-TiO 2 film, which can efficiently broaden the absorption spectra range, separate and transfer charge carriers, reduce recombination loss, and improve photovoltaic response, with a sensitization shell of CdS and a passivation shell of ZnS. A multisignal-amplified photoelectrochemical platform was fabricated by further modifying this film with a combination of biotin–DEVD–peptide (Biotin–Gly–Asp–Gly–Asp–Glu–Val–Asp–Gly–Cys) (which is specifically cleaved by caspase-3) and streptavidin-labeled alkaline phosphatase (SA-ALP). Under the enzymatic catalysis of ALP with the substrate 2-phospho- L -ascorbic acid trisodium salt (AAP), ascorbic acid (AA) was generated as a better electron donor, leading to increased photocurrent output. The activity of caspase-3, which depends on the amount of residual peptide on the electrode, was inversely proportional to the amount of AA. By monitoring the variation of photocurrent caused by AA, caspase-3 activity and the therapeutic effect of nilotinib (a special medicine of chronic myeloid leukemia, CML) were indirectly detected and evaluated. The photoelectrochemical platform can be used as a potential evaluation system for monitoring caspase-3 activity and drug effects.
研究领域:
生物医学工程
·
光电化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2016
·Vol. 18
·期 12
·1-16
·
IF 2.101
Li Zhenzhen,Zhang Qiyi,Huang Huaying,Ren Changjing,Pan Yujin,Wang Qing,Zhao Qiang
In the experiments, high-quality, water-soluble and near-infrared (NIR)-emitting CdSeTe and CdSeTe/CdS quantum dots (QDs) were successfully prepared. The average size of CdSeTe⁄CdS QDs was 7.68 nm and CdSeTe QDs was 4.33 nm. Arginine-glycine-aspartic-serine acid (RGDS) peptides were linked to CdSeTe/CdS QDs by N-(3-(dimethylamino)propyl)-N′-ehtylcarbodiimide hydrochloride (EDC) and N′-hydroxysuccinimide (NHS). The prepared RGDS-tagged NIR CdSeTe/CdS QDs (denoted as RGDS-CdSeTe/CdS) had an average diameter of 24.83 nm and were used for cancer cell immunofluorescence imaging. The characteristics of RGDS-conjugated CdSeTe/CdS such as morphology, structure, spectra, stability, cytotoxicity, and near-infrared microscopic imaging were investigated in detail. HepG2 cells were incubated with the novel fluorescent probe (RGDS-CdSeTe/CdS), which realized immunofluorescence targeting and imaging. The results reported here open up new perspectives for integrin-targeted near-infrared imaging and may aid in tumor detection including imaging-guided surgery.
研究领域:
生物医学工程
·
纳米医学
·
肿瘤学
✓ 已验证
产品关联
DOI
高影响因子
LUMINESCENCE
·
2021
·Vol. 36
·期 6
·1513-1524
·
IF 2.464
Huan Zhang,Zhenzhen Li,Huaying Huang,Si Ouyang,Yiqing Deng,Qiang Zhao
Near-infrared (NIR) core–shell CdSeTe/CdS quantum dots (QDs) modified with l -cysteine were synthesized in aqueous solution. The QDs had a special NIR-emitting spectrum, high fluorescence stability and low cytotoxicity. In addition, they exhibited an obvious fluorescence quenching when Cu 2+ was present. An NIR nanosensor was prepared for rapidly, sensitively, and selectively determining Cu 2+ in solution quantitatively and monitoring the changes in Cu 2+ in cells with fluorescence imaging in a semiquantitative way. The linear relationship between the relative fluorescence intensity (F 0 /F) and the concentration of Cu 2+ from 5.12 × 10 −8 M to 2.56 × 10 −5 M in solution was observed using an NIR fluorescence spectrophotometer with R 2 equal to 0.9958. Moreover, in the experiment with the fluorescence microscope, F 0 /F versus the concentration of Cu 2+ from 5.00 × 10 −8 M to 7.68 × 10 −6 M also showed a good linear relationship with R 2 equal to 0.9817. Practical water sample ion detecting experiments had good accuracy and recovery rates. Cell experiments showed that the NIR imaging intensity of cells was inversely proportional to the concentration of copper ions, therefore NIR QDs have great potential for detection of metal ions in solution and in cells.
研究领域:
生物化学
·
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）