State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Luminescence. 2011 Mar-Apr;26(2):136-41. doi: 10.1002/bio.1196.
In this paper, silver enhancement of nanogold labels coupled with chemiluminescence detection was developed for ultrasensitive immunoassay of Salmonella based upon antigen-antibody immunoreaction. Polyclonal rabbit anti-Salmonella sp. antibodies (pAb) were employed to establish the analytical protocol. The pAb coated onto ELISA microwell plates and Au nanoparticles (Au NPs) conjugated pAb capture target Salmonella to form a sandwich-type complex. Silver then was in situ deposited around the Au NPs core and resulted in the signal amplification. In consequence, silver was dissolved to form Ag(+) and a sensitive chemiluminescence based on the Ag(+)-K2S2O8-Mn(2+)-luminol system was coupled for further signal amplification. Under the optimized conditions, the chemiluminescent intensity is proportional to target Salmonella over the range of 5-1038 cfu mL(-1) with a detection limit of 5 cfu mL(-1). The relative standard deviation for 11 measurements of about 50-100 cfu/mL target Salmonella is 4.7%. The proposed method was successfully applied to measure Salmonella in food samples and the results are identical to those of the offical standard method of China. These offer us a more powerful tool for ultrasensitive assay of foodborne pathogens.
本文提出了一种基于抗原-抗体免疫反应的银增强纳米金标记物结合化学发光检测的方法，用于沙门氏菌的超灵敏免疫分析。多克隆兔抗沙门氏菌抗体（pAb）被用于建立分析方案。pAb 被涂覆到 ELISA 微孔板上，Au 纳米粒子（Au NPs）结合 pAb 捕获目标沙门氏菌，形成三明治型复合物。然后，银在 Au NPs 核心周围原位沉积，导致信号放大。结果，银被溶解形成 Ag(+)，并结合 Ag(+)-K2S2O8-Mn(2+)-luminol 体系进行进一步的信号放大。在优化条件下，化学发光强度与 5-1038 cfu mL(-1)范围内的目标沙门氏菌呈正比，检测限为 5 cfu mL(-1)。对于约 50-100 cfu/mL 目标沙门氏菌的 11 次测量的相对标准偏差为 4.7%。该方法成功应用于食品样品中沙门氏菌的测定，结果与中国官方标准方法一致。这些为我们提供了一种更强大的工具，用于超灵敏检测食源性致病菌。
