An effective electrochemical signal amplification strategy based on enzyme membrane modification and redox probe immobilization was proposed to construct an amperometric immunosensor.L-cysteine@ferrocene functionalize...An effective electrochemical signal amplification strategy based on enzyme membrane modification and redox probe immobilization was proposed to construct an amperometric immunosensor.L-cysteine@ferrocene functionalized chitosan,which possessed not only efficient redox-activity but also excellent film-forming ability,was coated on the bare glass carbon electrode. Moreover,the thiol groups(SH)in the ferrocenyl compound were used for gold nanoparticles immobilization via the strong bonding interaction,which could further be utilized for the immobilization of antibody biomolecules with well-retained bioactivities.Finally,glucose oxidase(GOD)as the enzyme membrane was employed to block the possible remaining active sites and avoid the nonspecific adsorption.With the excellent electrocatalytic properties of GOD towards glucose,the amplification of antigen-antibody interaction and the enhanced sensitivity could be achieved.Under the optimal conditions,the linear range of the proposed immunosensor for the determination of carcinoembryonic antigen(CEA)was from 0.05 to 100 ng/mL with a detection limit of 0.02 ng/mL(S/N=3).Moreover,the immunosensor exhibited good selectivity,stability and reproducibility, which provided a promising potential for clinical immunoassay.展开更多
A micro amperometric immunosensor with the sensitive area of only 1mm^2 was fabricated on silicon using the technique of Micro-Electro-Mechanical Systems (MEMS).A double exposure of SU-8 photoresist process was develo...A micro amperometric immunosensor with the sensitive area of only 1mm^2 was fabricated on silicon using the technique of Micro-Electro-Mechanical Systems (MEMS).A double exposure of SU-8 photoresist process was developed to create both the sensitive pool and reaction pool.Antibody was immobilized via cross-linking with glutaraldehyde on the sensitive area of the electrode surface,which was electropolymerized with polypyrrole previously.The immunosensor was characterized by detection of human immunoglobulin G (HIgG).The immunosensor displayed a good linear response to HIgG concentrations between 5ng/ml and 255ng/ml and demonstrated a fast response time of 3 minutes.展开更多
Based on MEMS technology,immunosensor with an'Au,Pt,Pt'three-microelectrode system enclosed in a SU-8 micro pool was fabricated.Employing SAMs technique,the Au electrode was modified by cysteamine(Cys)to assem...Based on MEMS technology,immunosensor with an'Au,Pt,Pt'three-microelectrode system enclosed in a SU-8 micro pool was fabricated.Employing SAMs technique,the Au electrode was modified by cysteamine(Cys)to assemble gold nanopanicles(nanogold)layer,subsequently,a layer of protein G(PG)was immobilized on nanogold layer to further capture antibody orientedly.Compared with the immunosensors using bulky gold electrode and direct PG binding to electrode immobilization technique for antibody,it has attractive advantages,such as miniaturization,good compatibility,broad linear range for human immunoglobulin(HIgG)and easy to be designed into array.展开更多
Label-free immunoassay is confronted with a great challenge that its insufficient sensitivity for low concentration analytes,which can be assigned to the low catalytic efficiency of modified materials towards electroa...Label-free immunoassay is confronted with a great challenge that its insufficient sensitivity for low concentration analytes,which can be assigned to the low catalytic efficiency of modified materials towards electroactive molecules.Herein,a universal MOF nanozyme-induced catalytic amplification strategy was proposed for constructing highly sensitive label-free electrochemical immunoassay.Specifically,the synthesized Cu Fe-MOF nanozyme with superior peroxidase(POD)-like activity,regarding as a MOF nanozyme model,can catalyze hydrogen peroxide to produce hydroxyl radicals(·OH),which can efficiently oxidize electroactive probe(such as 1,2-phenylenediamine(o-PD))accompanying with intense electrochemical signals.Modification of MOF nanozyme on the electrode and capture of antibodies for binding target antigens hinder the catalytic process of MOF nanozyme toward o-PD,resulting in a gradual decrease in electrochemical signal with increasing target antigen concentration,enabling quantitative label-free immunoassay.Thus,a highly sensitive label-free immunosensor using MOF nanozyme-induced catalytic amplification achieved effective detection of Immunoglobulin G(Ig G)with a wide linear range of 0.001-50 ng/mL and low detection limit of 0.45 pg/mL.This work proposes a promising nanozyme-induced catalytic amplification strategy for the development of label-free electrochemical immunoassay.展开更多
A novel amperometric immunosensor based on the micro electromechanical systems （MEMS） technology, using protein A and self-assembled monolayers （SAMs） for the orientation-controlled immobilization of antibodies, h...A novel amperometric immunosensor based on the micro electromechanical systems （MEMS） technology, using protein A and self-assembled monolayers （SAMs） for the orientation-controlled immobilization of antibodies, has been developed. Using MEMS technology, an ＂Au, Pt, Pt＂ three-microelectrode system enclosed in a SU-8 micro pool was fabricated. Employing SAMs, a monolayer of protein A was immobilized on the cysteamine modified Au electrode to achieve the orientation-controlled immobilization of the human immunoglobulin （HIgG） antibody. The immunosensor aimed at low unit cost, small dimension, high level of integration and the prospect of a biosensor system-on-a-chip. Cyclic voltammetry and chronoamperometry were conducted to characterize the immunosensor. Compared with the traditional immunosensor using bulky gold electrode or screen-printed electrode and the procedure directly binding protein A to electrode for immobilization of antibodies, it had attractive advantages, such as miniaturization, compatibility with CMOS technology, fast response （30 s）, broad linear range （50-400 pg/L） and low detection limit （10 pg/L） for HIgG. In addition, this immunosensor was easy to be designed into micro array and to realize the simultaneously multi-parameter detection.展开更多
基于电化学聚合将蛋白A(staphylococcal protein A)与吡咯掺杂后共聚于电极表面的新方法设计传感界面,结合采用微机电系统(micro electro mechanical systems,MEMS)技术制备的两电极系统,开发了一种新型的利用电聚合引入蛋白A进而固定...基于电化学聚合将蛋白A(staphylococcal protein A)与吡咯掺杂后共聚于电极表面的新方法设计传感界面,结合采用微机电系统(micro electro mechanical systems,MEMS)技术制备的两电极系统,开发了一种新型的利用电聚合引入蛋白A进而固定抗体、提高检测性能的安培型免疫微传感器,并应用于沙门氏菌(Sal-monella typhimurium,S.typhi)的检测。考察了传感器检测沙门氏菌的响应特性,优化了相关实验条件及参数,并结合扫描电镜(scanning electron microscopy,SEM)图像验证了该抗体固定方法的有效性。实验表明,采用电化学聚合方法固定蛋白A进行敏感膜修饰,操作简便省时(<10min)、可控性强,试剂用量少(10μL),能够有效改善抗体固定效果,提高传感器检测性能,适于微型免疫传感器的表面修饰研究。以此设计的安培型免疫微传感器能够检测100cfu/mL沙门氏菌溶液,具有良好的重复性和特异性。展开更多
基金financially supported by the National Natural Science Foundation of China(20675064)the Ministry of Education of China(708073)+1 种基金the Natural Science Foundation of Chongqing City (CSTC-2009BA1003)High Technology Project Foundation of Southwest University(XSGX 02)
文摘An effective electrochemical signal amplification strategy based on enzyme membrane modification and redox probe immobilization was proposed to construct an amperometric immunosensor.L-cysteine@ferrocene functionalized chitosan,which possessed not only efficient redox-activity but also excellent film-forming ability,was coated on the bare glass carbon electrode. Moreover,the thiol groups(SH)in the ferrocenyl compound were used for gold nanoparticles immobilization via the strong bonding interaction,which could further be utilized for the immobilization of antibody biomolecules with well-retained bioactivities.Finally,glucose oxidase(GOD)as the enzyme membrane was employed to block the possible remaining active sites and avoid the nonspecific adsorption.With the excellent electrocatalytic properties of GOD towards glucose,the amplification of antigen-antibody interaction and the enhanced sensitivity could be achieved.Under the optimal conditions,the linear range of the proposed immunosensor for the determination of carcinoembryonic antigen(CEA)was from 0.05 to 100 ng/mL with a detection limit of 0.02 ng/mL(S/N=3).Moreover,the immunosensor exhibited good selectivity,stability and reproducibility, which provided a promising potential for clinical immunoassay.
基金The authors greatly acknowledge the financial support from the National Natural Science Foundation of China （Grant No. 90307014）
文摘A micro amperometric immunosensor with the sensitive area of only 1mm^2 was fabricated on silicon using the technique of Micro-Electro-Mechanical Systems (MEMS).A double exposure of SU-8 photoresist process was developed to create both the sensitive pool and reaction pool.Antibody was immobilized via cross-linking with glutaraldehyde on the sensitive area of the electrode surface,which was electropolymerized with polypyrrole previously.The immunosensor was characterized by detection of human immunoglobulin G (HIgG).The immunosensor displayed a good linear response to HIgG concentrations between 5ng/ml and 255ng/ml and demonstrated a fast response time of 3 minutes.
基金This work is supported by the National Natural Science Foundation of China （Grant No. 90307014）.
文摘Based on MEMS technology,immunosensor with an'Au,Pt,Pt'three-microelectrode system enclosed in a SU-8 micro pool was fabricated.Employing SAMs technique,the Au electrode was modified by cysteamine(Cys)to assemble gold nanopanicles(nanogold)layer,subsequently,a layer of protein G(PG)was immobilized on nanogold layer to further capture antibody orientedly.Compared with the immunosensors using bulky gold electrode and direct PG binding to electrode immobilization technique for antibody,it has attractive advantages,such as miniaturization,good compatibility,broad linear range for human immunoglobulin(HIgG)and easy to be designed into array.
基金financially supported by National Natural Science Foundation of China(Nos.21575125,82172345 and 81573220)the National Natural Science Foundation of Jiangsu Province(No.BK20221370,BK20221281)+5 种基金Key University Natural Science Foundation of Jiangsu-Province(No.20KJA150004)the Project for Science and Technology of Yangzhou(Nos.YZ2022074,YZ2020076)Project for Yangzhou City and Yangzhou University corporation(No.YZ2023204)Cross cooperation project of Subei Peoples’Hospital of Jiangsu Province(No.SBJC220009)Open Research Fund of State Key Laboratory of Analytical Chemistry for Life Science(No.SKLACLS2405)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX22_3462)。
文摘Label-free immunoassay is confronted with a great challenge that its insufficient sensitivity for low concentration analytes,which can be assigned to the low catalytic efficiency of modified materials towards electroactive molecules.Herein,a universal MOF nanozyme-induced catalytic amplification strategy was proposed for constructing highly sensitive label-free electrochemical immunoassay.Specifically,the synthesized Cu Fe-MOF nanozyme with superior peroxidase(POD)-like activity,regarding as a MOF nanozyme model,can catalyze hydrogen peroxide to produce hydroxyl radicals(·OH),which can efficiently oxidize electroactive probe(such as 1,2-phenylenediamine(o-PD))accompanying with intense electrochemical signals.Modification of MOF nanozyme on the electrode and capture of antibodies for binding target antigens hinder the catalytic process of MOF nanozyme toward o-PD,resulting in a gradual decrease in electrochemical signal with increasing target antigen concentration,enabling quantitative label-free immunoassay.Thus,a highly sensitive label-free immunosensor using MOF nanozyme-induced catalytic amplification achieved effective detection of Immunoglobulin G(Ig G)with a wide linear range of 0.001-50 ng/mL and low detection limit of 0.45 pg/mL.This work proposes a promising nanozyme-induced catalytic amplification strategy for the development of label-free electrochemical immunoassay.
基金supported by the National Natural Science Foundation of China(Grant No.90307014).
文摘A novel amperometric immunosensor based on the micro electromechanical systems （MEMS） technology, using protein A and self-assembled monolayers （SAMs） for the orientation-controlled immobilization of antibodies, has been developed. Using MEMS technology, an ＂Au, Pt, Pt＂ three-microelectrode system enclosed in a SU-8 micro pool was fabricated. Employing SAMs, a monolayer of protein A was immobilized on the cysteamine modified Au electrode to achieve the orientation-controlled immobilization of the human immunoglobulin （HIgG） antibody. The immunosensor aimed at low unit cost, small dimension, high level of integration and the prospect of a biosensor system-on-a-chip. Cyclic voltammetry and chronoamperometry were conducted to characterize the immunosensor. Compared with the traditional immunosensor using bulky gold electrode or screen-printed electrode and the procedure directly binding protein A to electrode for immobilization of antibodies, it had attractive advantages, such as miniaturization, compatibility with CMOS technology, fast response （30 s）, broad linear range （50-400 pg/L） and low detection limit （10 pg/L） for HIgG. In addition, this immunosensor was easy to be designed into micro array and to realize the simultaneously multi-parameter detection.
文摘基于电化学聚合将蛋白A(staphylococcal protein A)与吡咯掺杂后共聚于电极表面的新方法设计传感界面,结合采用微机电系统(micro electro mechanical systems,MEMS)技术制备的两电极系统,开发了一种新型的利用电聚合引入蛋白A进而固定抗体、提高检测性能的安培型免疫微传感器,并应用于沙门氏菌(Sal-monella typhimurium,S.typhi)的检测。考察了传感器检测沙门氏菌的响应特性,优化了相关实验条件及参数,并结合扫描电镜(scanning electron microscopy,SEM)图像验证了该抗体固定方法的有效性。实验表明,采用电化学聚合方法固定蛋白A进行敏感膜修饰,操作简便省时(<10min)、可控性强,试剂用量少(10μL),能够有效改善抗体固定效果,提高传感器检测性能,适于微型免疫传感器的表面修饰研究。以此设计的安培型免疫微传感器能够检测100cfu/mL沙门氏菌溶液,具有良好的重复性和特异性。
