多壁碳纳米管/DMF复合物4-SPCE福氏志贺氏菌酶免疫传感器的研制

Developing Shigella flexneri enzymatic immunosensor based on MWCNT/DMF composite and 4-SPCE

利用戊二醛交联法将辣根过氧化物酶标记的福氏志贺氏菌抗体固定在多壁碳纳米管修饰的四通道丝网印刷碳电极表面,制备了可用于检测福氏志贺氏菌的酶免疫传感器。采用循环伏安法对不同修饰电极进行电化学表征。根据抗原-抗体特异性结合形成的免疫复合物使敏感膜有效扩散截面积减小的特性,采用循环伏安法检测样品中的福氏志贺氏菌。在优化的实验条件下,该酶免疫传感器对福氏志贺氏菌的检测范围为104~109 cfu/mL,检出限为3.4×103 cfu/mL（S/N=3）。该酶传感器还具有较好的特异性、重现性、稳定性和准确性。

An immunosensor based on multi-walled carbon nanotubes/N,N-dimethylformamide（MWCNT/DMF） composite was successfully constructed.The horseradish peroxidase labeled antibodies to Shigella flexneri（HRP-anti-S.flexneri）was co-immobilized on the four-channel screen-printed carbon electrode surface by crosslinking with glutaraldehyde to form a combined sensing and electron transfer system.CV was carried out to characterize the electrochemical properties of different electrodes and to detect S.flexneri.When the antigen（S.flexneri） was bound to the antibody on the surface of the sensing film,a＂barrier＂occurred between the electrode and the redox centres in the bound HRP.Under optimal conditions,concentrations of S.flexneri from 104 to 109 cfu/mL could be detected,with a detection limit of 3.4 ×103 cfu/mL（S/N =3）.The immunosensor showed satisfactory selectivity,reproducibility,stability and accuracy.