The effect of deposition temperature on the morphology and optoelectronic performance of Ge/Si QDs grown by magnetron sputtering under low Ge deposition(~4 nm)was investigated by atomic force microscopy,Raman spectros...The effect of deposition temperature on the morphology and optoelectronic performance of Ge/Si QDs grown by magnetron sputtering under low Ge deposition(~4 nm)was investigated by atomic force microscopy,Raman spectroscopy,and photoluminescence(PL)tests.The experimental results indicate that temperatures higher than 750℃effectively increase the crystallization rate and surface smoothness of the Si buffer layer,and temperatures higher than 600℃significantly enhance the migration ability of Ge atoms,thus increasing the probability of Ge atoms meeting and nucleating to form QDs on Si buffer layer,but an excessively high temperature will cause the QDs to undergo an Ostwald ripening process and thus develop into super large islands.In addition,some PL peaks were observed in samples containing small-sized,high-density Ge QDs,the photoelectric properties reflected by these peaks were in good agreement with the corresponding structural characteristics of the grown QDs.Our results demonstrate the viability of preparing high-quality QDs by magnetron sputtering at high deposition rate,and the temperature effect is expected to work in conjunction with other controllable factors to further regulate QD growth,which paves an effective way for the industrial production of QDs that can be used in future devices.展开更多
采用简单液相沉积法制备了分级结构Cd S QDs/Bi OCl复合光催化剂,以XRD,SEM,TEM,HRTEM,XPS,EDS,UV-Vis DRS,PL等测试方法分别表征了样品的物相、形貌、组成、元素含量、光吸收性能以及光电特性,并以罗丹明B(Rh B)和苯酚为模型污染物,分...采用简单液相沉积法制备了分级结构Cd S QDs/Bi OCl复合光催化剂,以XRD,SEM,TEM,HRTEM,XPS,EDS,UV-Vis DRS,PL等测试方法分别表征了样品的物相、形貌、组成、元素含量、光吸收性能以及光电特性,并以罗丹明B(Rh B)和苯酚为模型污染物,分别在可见光和紫外光下评价Cd S QDs/Bi OCl复合光催化剂的催化性能。测试结果表明,粒径为5.5μm的Bi OCl微球由大量纳米片有序堆积而成,所负载的粒径为10~20 nm的Cd S QDs均匀分布在Bi OCl纳米片表面。与纯Bi OCl和Cd S QDs/Bi OCl相比,Cd S QDs/Bi OCl-3%表现出最佳的光催化性能,其对Rh B和苯酚的降解速率常数分别是纯Bi OCl的2.6倍和5.3倍。Cd S QDs/Bi OCl复合光催化剂性能的提高可归结于,分级结构Bi OCl有效防止了片层堆积,有助于Cd S QDs的负载,另外,Cd S QDs的负载拓展了复合光催化剂的光吸收性能,均匀分布的Cd S QDs与Bi OCl形成的异质结促进了光生电子-空穴对的有效分离。展开更多
Semiconductor quantum dots(QDs) were used for labeling many biomacromolecules and small molecules,but it remains a challenge to couple it with short active peptides without any limitation,which play critical roles in ...Semiconductor quantum dots(QDs) were used for labeling many biomacromolecules and small molecules,but it remains a challenge to couple it with short active peptides without any limitation,which play critical roles in many physiological processes.Several coupling methods known about QDs and short peptides have some limitations.In this research,we report a method for the synthesis of QDs labeled peptides to be appropriate to any short peptide.The QDs(CdTe)-labeled short peptides were verified and characterized by RP-HPLC.The result shows that the surface of the T cell treated with QDs-TP5 emits yellow fluoresence.These results indicate that QDs-TP5 tends to aggregate on the surface of T cells.They were applied to monitoring the specific binding between the immune peptides and T cell surface receptors.The binding and the resultant fluorescence were observed and monitored by fluorescence microscope in vitro.The QDs-labeled immune peptides provide a powerful method for studying the immune modulating activity of TP5 in vivo.展开更多
目的制备毒性低,生物相容性好的新型半导体量子点。方法以还原型谷胱甘肽（GSH）为硫源和稳定剂,采用水热法合成Cd Te/Cd S QDs。结果制备的GSH包裹的Cd Te/Cd S QDs波长范围覆盖400~800 nm的区域,量子产率高达83.1%,平均粒径约为3 nm...目的制备毒性低,生物相容性好的新型半导体量子点。方法以还原型谷胱甘肽（GSH）为硫源和稳定剂,采用水热法合成Cd Te/Cd S QDs。结果制备的GSH包裹的Cd Te/Cd S QDs波长范围覆盖400~800 nm的区域,量子产率高达83.1%,平均粒径约为3 nm。结论该Cd Te/Cd S QDs制备方法简便,成本低,有效降低了量子点生物毒性。展开更多
In this work the enhanced molecularly imprinted optosensing material based on graphene oxide-quantum dots （ GO- QDs） was synthesized for highly selective and sensitive specific recognition of the target protein, bov...In this work the enhanced molecularly imprinted optosensing material based on graphene oxide-quantum dots （ GO- QDs） was synthesized for highly selective and sensitive specific recognition of the target protein, bovine serum albumin （BSA）. Here, GO was introduced to enhance the efficiency of mass-transfer in recognition of target protein. Molecularly imprinted polymer coated GO-QDs using BSA as template （BMIP-coated GO-QDs ） exhibited a fast mass-transfer speed, which could be ascribed to the high volume of efficient surface area and high target recognition efficiency of the synthesized nanoscale device. Under optimal conditions, it was found that the BSA as target protein could remarkably quench the relative fluorescence intensity of BMIP- coated GO-QDs linearly in a concentration-dependent manner that was best described by a Stern-Volmer equation. The Ksv （Stern- Volmer constant） for template BSA was much higher than bovine hemoglobin （BHb） and lysozyme （Lyz）, implying a highly selective recognition ability of the BMIP-coated GO-QDs to BSA. This enhanced fluorescent nanoscale device may provide opportunities to develop a system that is efficient and effective and has potential in the design of highly effective fluorescent receptor for recognition of target protein in Droteomics studies.展开更多
The active oxygen species in the catalytic oxidation system of Fe(Ⅲ)PcTs-t-BuOOH were identified,and the mechanism of the catalytic oxidation of phenolic substrates was proposed.Quinone imine molecules,the main produ...The active oxygen species in the catalytic oxidation system of Fe(Ⅲ)PcTs-t-BuOOH were identified,and the mechanism of the catalytic oxidation of phenolic substrates was proposed.Quinone imine molecules,the main products of catalytic oxidation reaction,can be adsorbed on the surface of CdTe QDs,resulting in their fluorescence quenching.A dual function of catalytic oxidation and fluorescence sensing was developed for the determination of dichlorophenol(DCP)based on the Fe(Ⅲ)PcTs-BuOOH-CdTe QDs system.The linear detection range of DCP was 1×10^(-6)-1.3×10^(-4) mol/L,and the detection limit 2.4×10^(-7) mol/L.This method was characterized by high selectivity,good repeatability and desirable stability,presenting promising potentials for analyzing DCP concentration in real water samples.展开更多
基金Founded by the National Key Research and Development Program(No.2021YFB3802400)the National Natural Science Foundation of China(No.52161037)the Basic Research Project of Yunnan Province(No.202001AU070112)。
文摘The effect of deposition temperature on the morphology and optoelectronic performance of Ge/Si QDs grown by magnetron sputtering under low Ge deposition(~4 nm)was investigated by atomic force microscopy,Raman spectroscopy,and photoluminescence(PL)tests.The experimental results indicate that temperatures higher than 750℃effectively increase the crystallization rate and surface smoothness of the Si buffer layer,and temperatures higher than 600℃significantly enhance the migration ability of Ge atoms,thus increasing the probability of Ge atoms meeting and nucleating to form QDs on Si buffer layer,but an excessively high temperature will cause the QDs to undergo an Ostwald ripening process and thus develop into super large islands.In addition,some PL peaks were observed in samples containing small-sized,high-density Ge QDs,the photoelectric properties reflected by these peaks were in good agreement with the corresponding structural characteristics of the grown QDs.Our results demonstrate the viability of preparing high-quality QDs by magnetron sputtering at high deposition rate,and the temperature effect is expected to work in conjunction with other controllable factors to further regulate QD growth,which paves an effective way for the industrial production of QDs that can be used in future devices.
文摘采用简单液相沉积法制备了分级结构Cd S QDs/Bi OCl复合光催化剂,以XRD,SEM,TEM,HRTEM,XPS,EDS,UV-Vis DRS,PL等测试方法分别表征了样品的物相、形貌、组成、元素含量、光吸收性能以及光电特性,并以罗丹明B(Rh B)和苯酚为模型污染物,分别在可见光和紫外光下评价Cd S QDs/Bi OCl复合光催化剂的催化性能。测试结果表明,粒径为5.5μm的Bi OCl微球由大量纳米片有序堆积而成,所负载的粒径为10~20 nm的Cd S QDs均匀分布在Bi OCl纳米片表面。与纯Bi OCl和Cd S QDs/Bi OCl相比,Cd S QDs/Bi OCl-3%表现出最佳的光催化性能,其对Rh B和苯酚的降解速率常数分别是纯Bi OCl的2.6倍和5.3倍。Cd S QDs/Bi OCl复合光催化剂性能的提高可归结于,分级结构Bi OCl有效防止了片层堆积,有助于Cd S QDs的负载,另外,Cd S QDs的负载拓展了复合光催化剂的光吸收性能,均匀分布的Cd S QDs与Bi OCl形成的异质结促进了光生电子-空穴对的有效分离。
文摘Semiconductor quantum dots(QDs) were used for labeling many biomacromolecules and small molecules,but it remains a challenge to couple it with short active peptides without any limitation,which play critical roles in many physiological processes.Several coupling methods known about QDs and short peptides have some limitations.In this research,we report a method for the synthesis of QDs labeled peptides to be appropriate to any short peptide.The QDs(CdTe)-labeled short peptides were verified and characterized by RP-HPLC.The result shows that the surface of the T cell treated with QDs-TP5 emits yellow fluoresence.These results indicate that QDs-TP5 tends to aggregate on the surface of T cells.They were applied to monitoring the specific binding between the immune peptides and T cell surface receptors.The binding and the resultant fluorescence were observed and monitored by fluorescence microscope in vitro.The QDs-labeled immune peptides provide a powerful method for studying the immune modulating activity of TP5 in vivo.
文摘目的制备毒性低,生物相容性好的新型半导体量子点。方法以还原型谷胱甘肽（GSH）为硫源和稳定剂,采用水热法合成Cd Te/Cd S QDs。结果制备的GSH包裹的Cd Te/Cd S QDs波长范围覆盖400~800 nm的区域,量子产率高达83.1%,平均粒径约为3 nm。结论该Cd Te/Cd S QDs制备方法简便,成本低,有效降低了量子点生物毒性。
文摘In this work the enhanced molecularly imprinted optosensing material based on graphene oxide-quantum dots （ GO- QDs） was synthesized for highly selective and sensitive specific recognition of the target protein, bovine serum albumin （BSA）. Here, GO was introduced to enhance the efficiency of mass-transfer in recognition of target protein. Molecularly imprinted polymer coated GO-QDs using BSA as template （BMIP-coated GO-QDs ） exhibited a fast mass-transfer speed, which could be ascribed to the high volume of efficient surface area and high target recognition efficiency of the synthesized nanoscale device. Under optimal conditions, it was found that the BSA as target protein could remarkably quench the relative fluorescence intensity of BMIP- coated GO-QDs linearly in a concentration-dependent manner that was best described by a Stern-Volmer equation. The Ksv （Stern- Volmer constant） for template BSA was much higher than bovine hemoglobin （BHb） and lysozyme （Lyz）, implying a highly selective recognition ability of the BMIP-coated GO-QDs to BSA. This enhanced fluorescent nanoscale device may provide opportunities to develop a system that is efficient and effective and has potential in the design of highly effective fluorescent receptor for recognition of target protein in Droteomics studies.
基金Funded by the National Natural Science Foundation of China(No.61205062)the Hubei Provincial Department of Education Scientific Research Program Guidance Project(No.B2020282)。
文摘The active oxygen species in the catalytic oxidation system of Fe(Ⅲ)PcTs-t-BuOOH were identified,and the mechanism of the catalytic oxidation of phenolic substrates was proposed.Quinone imine molecules,the main products of catalytic oxidation reaction,can be adsorbed on the surface of CdTe QDs,resulting in their fluorescence quenching.A dual function of catalytic oxidation and fluorescence sensing was developed for the determination of dichlorophenol(DCP)based on the Fe(Ⅲ)PcTs-BuOOH-CdTe QDs system.The linear detection range of DCP was 1×10^(-6)-1.3×10^(-4) mol/L,and the detection limit 2.4×10^(-7) mol/L.This method was characterized by high selectivity,good repeatability and desirable stability,presenting promising potentials for analyzing DCP concentration in real water samples.
