The preparation and application of supported gold and copper catalysts are fundamentally and practically very important.Herein,we confirm that the Au-Cu promoted In_(2)O_(3) catalyst demonstrates a significant electro...The preparation and application of supported gold and copper catalysts are fundamentally and practically very important.Herein,we confirm that the Au-Cu promoted In_(2)O_(3) catalyst demonstrates a significant electronic metal-support interaction(EMSI),which plays a critical role in CO_(2) hydrogenation to methanol and leads to significantly improved activity,compared to the mono-metallic Au and Cu promoted In_(2)O_(3)catalysts.This interaction arises from electron transfer between the oxygen deficient In_(2)O_(3) support and the bimetallic clusters,rendering both Au and Cu clusters positively charged.The presence of Cu^(3+)stabilizes and optimizes the content of oxygen vacancies,leading to a more pronounced positive charge on Au clusters(Au^(3+)).The ability to activate H_(2) is thus enhanced.CO adsorption on Au-Cu/In_(2)O_(3) is also stronger than Au/In_(2)O_(3).This results in higher methanol selectivity of Au-Cu/In_(2)O_(3),with which CO hydrogenation pathway is taken for CO_(2) hydrogenation to methanol.The enhanced H_(2) activation and stronger CO adsorption over Au-Cu/In_(2)O_(3) are key factors in boosting the activity for methanol formation from CO_(2)hvdrogenation.展开更多
Early detection and treatment of colorectal cancer can effectively reduce the harm caused to patients.However,early symptoms are not obvious.Exosomes are extracellular vesicles that carry information between cells cir...Early detection and treatment of colorectal cancer can effectively reduce the harm caused to patients.However,early symptoms are not obvious.Exosomes are extracellular vesicles that carry information between cells circulating in the human body.Despite the critical importance of tumor-derived exosomes for early cancer detection,prognosis,and treatment guidance,sensitive detection of exosomes remains challenging.We report a novel immunosensor for the detection of exosomes using graphene oxide(GO)/Au/Ag as the electrochemical sensing platform and spherical Au@PtPd porous nanoparticles to provide signal amplification.A large-surface-area GO/Au/Ag-modified screen-printed carbon electrode(SPCE)is used to immobilize CD63 aptamers.The prepared strawberry-like Au@PtPd demonstrates improved sensitivity and electrocatalytic activity with increasing aptamer load.Meanwhile,its good conductivity accelerates the electron transfer rate on the SPCE.The immunosensor exhibits a linear range(100–1.0×10^(6)exosomes·μl^(−1))and a detection limit of 23 exosomes·μl^(−1).Furthermore,its potential for the detection of exosomes provides a new clinical application for early diagnosis of colorectal tumors.展开更多
This article presented a facile fabrication process for polydimethylsiloxane(PDMS)composite gold nanotris⁃octahedra(Au NTOH)for a flexible SERS sensor with high sensitivity.Specifically,Au NTOH with excellent SERS beh...This article presented a facile fabrication process for polydimethylsiloxane(PDMS)composite gold nanotris⁃octahedra(Au NTOH)for a flexible SERS sensor with high sensitivity.Specifically,Au NTOH with excellent SERS behaviors was synthesized using a seed-mediated growth method and the dimensions of the Au NTOH was easily tuned.In addition,the influence of size on the SERS performance of their monolayers was systematically investigated,and the Au NTOH with the size of 61 nm possessed the best SERS performance.Importantly,a hydrophilic-substrateassisted interfacial self-assembled monolayer transfer technique was proposed to transfer Au NTOH onto PDMS films,resulting in forming flexible and transparent Au NTOH@PDMS substrates.Furthermore,the excellent signal homoge⁃neity of this substrate was demonstrated and the sensitivity was verified by a measurement of crystal violet(CV)as low as 1×10^(-8) mol/L.As a result,this SERS sensor is progressing for applying in the identification of trace contaminants in broad fields.展开更多
基金supported by the National Natural Science Foundation of China(22138009)the Fundamental Research Funds for the Central Universities of China。
文摘The preparation and application of supported gold and copper catalysts are fundamentally and practically very important.Herein,we confirm that the Au-Cu promoted In_(2)O_(3) catalyst demonstrates a significant electronic metal-support interaction(EMSI),which plays a critical role in CO_(2) hydrogenation to methanol and leads to significantly improved activity,compared to the mono-metallic Au and Cu promoted In_(2)O_(3)catalysts.This interaction arises from electron transfer between the oxygen deficient In_(2)O_(3) support and the bimetallic clusters,rendering both Au and Cu clusters positively charged.The presence of Cu^(3+)stabilizes and optimizes the content of oxygen vacancies,leading to a more pronounced positive charge on Au clusters(Au^(3+)).The ability to activate H_(2) is thus enhanced.CO adsorption on Au-Cu/In_(2)O_(3) is also stronger than Au/In_(2)O_(3).This results in higher methanol selectivity of Au-Cu/In_(2)O_(3),with which CO hydrogenation pathway is taken for CO_(2) hydrogenation to methanol.The enhanced H_(2) activation and stronger CO adsorption over Au-Cu/In_(2)O_(3) are key factors in boosting the activity for methanol formation from CO_(2)hvdrogenation.
基金supported by National Natural Science Foundation of China(Grant No.12105239)the Science and Technology Projects of Henan Province(Grant No.232102310002).
文摘Early detection and treatment of colorectal cancer can effectively reduce the harm caused to patients.However,early symptoms are not obvious.Exosomes are extracellular vesicles that carry information between cells circulating in the human body.Despite the critical importance of tumor-derived exosomes for early cancer detection,prognosis,and treatment guidance,sensitive detection of exosomes remains challenging.We report a novel immunosensor for the detection of exosomes using graphene oxide(GO)/Au/Ag as the electrochemical sensing platform and spherical Au@PtPd porous nanoparticles to provide signal amplification.A large-surface-area GO/Au/Ag-modified screen-printed carbon electrode(SPCE)is used to immobilize CD63 aptamers.The prepared strawberry-like Au@PtPd demonstrates improved sensitivity and electrocatalytic activity with increasing aptamer load.Meanwhile,its good conductivity accelerates the electron transfer rate on the SPCE.The immunosensor exhibits a linear range(100–1.0×10^(6)exosomes·μl^(−1))and a detection limit of 23 exosomes·μl^(−1).Furthermore,its potential for the detection of exosomes provides a new clinical application for early diagnosis of colorectal tumors.
基金The National Natural Science Foundation of China(12274055)the Fundamental Research Funds for the Central Universities(04442024072)the Training Program of Innovation and Entrepreneurship for Undergraduates in Dalian Minzu University(202312026063)。
文摘This article presented a facile fabrication process for polydimethylsiloxane(PDMS)composite gold nanotris⁃octahedra(Au NTOH)for a flexible SERS sensor with high sensitivity.Specifically,Au NTOH with excellent SERS behaviors was synthesized using a seed-mediated growth method and the dimensions of the Au NTOH was easily tuned.In addition,the influence of size on the SERS performance of their monolayers was systematically investigated,and the Au NTOH with the size of 61 nm possessed the best SERS performance.Importantly,a hydrophilic-substrateassisted interfacial self-assembled monolayer transfer technique was proposed to transfer Au NTOH onto PDMS films,resulting in forming flexible and transparent Au NTOH@PDMS substrates.Furthermore,the excellent signal homoge⁃neity of this substrate was demonstrated and the sensitivity was verified by a measurement of crystal violet(CV)as low as 1×10^(-8) mol/L.As a result,this SERS sensor is progressing for applying in the identification of trace contaminants in broad fields.
