基于多孔金@铂纳米酶的比色型生物传感器用于检测牛乳中鼠伤寒沙门氏菌研究

Colorimetric biosensor based on porous gold@platinum nanocatalysts for detection of Salmonella typhimurium in milk

建立了一种快速、灵敏检测牛乳中鼠伤寒沙门氏菌ATCC 14028(Salmonella typhimurium,S. typhimurium)的方法。利用鼠伤寒沙门氏菌多克隆抗体(Anti-S. typhimurium-pAb)修饰磁珠(Magnetic nanoparticles, MNPs)形成免疫磁珠(MNPs@pAb),鼠伤寒沙门氏菌单克隆抗体(Anti-S. typhimurium-mAb)标记多孔金@铂纳米酶(gold@platinum nanocatalysts,Au@PtNCs)形成具有催化性能的免疫探针Au@PtNCs@mAb,与鼠伤寒沙门氏菌最终反应形成MNPs@pAb-S. typhimurium-Au@PtNCs@mAb复合物后磁分离富集,在过氧化氢存在下可催化显色底物3,3’,5,5’-四甲基联苯胺(H2O2-TMB)生成蓝色物质,并在652 nm处产生较强的特征吸收峰。在最佳条件下,最低检测限为81 CFU/mL,线性范围为97~9.7×10^(5) CFU/mL,实际牛乳样本加标实验中加标回收率为96.75%~101.75%,变异系数(CV)为1.10%~5.13%。该方法建立的比色型生物传感器具有简单、快速、灵敏等特性,可用于检测乳品中的鼠伤寒沙门氏菌。

A rapid and sensitive method for the detection of Salmonella typhimurium(S.typhimurium)ATCC 14028 in milk was established.Using S.typhimurium polyclonal antibody(Anti-S.typhimurium pAb)to modify magnetic nanoparticles(MNPs)to form immune magnetic beads(MNPs@pAb),and using S.typhimurium monoclonal antibody(Anti-S.typhimurium-mAb)to label porous gold@platinum nanocatalysts(Au@PtNCs)to form immune probes Au@PtNCs@mAb with catalytic properties,which reacted with S.typhimurium to form MNPs@pAb-S.typhimurium-Au@PtNCs@mAb complexes and undergo magnetic separation and enrichment.In the presence of hydrogen peroxide,the chromogenic substrates 3,3',5,5'tetramethylbenzidine(H2O2-TMB)can be catalyzed to generate blue substances,and a strong characteristic absorption peak is generated at 652 nm.Under optimal conditions,the minimum detection limit is 81 CFU/mL,and the linear range is 97-9.7×10^(5) CFU/mL,the recovery rate of standard addition in the actual milk sample standard addition experiment is 96.75%-101.75%,and the coefficient of variation(CV)is 1.10%-5.13%.The colorimetric biosensor established by this method is simple,rapid and sensitive.It can be used to detect S.typhimurium in dairy products and has reference significance for food safety detection.