In this study, a fluorescent (FL) aptasensor was developed for on-site detection of live Salmonella typhimurium (S.T.) and Vibrio parahaemolyticus (V.P.). Complementary DNA (cDNA) of aptamer (Apt)-functionalized multicolor polyhedral oligomeric silsesquioxane-perovskite quantum dots (cDNA-POSS-PQDs) were used as encoded probes and combined with dual-stirring-bar-assisted signal amplification for pathogen quantification. In this system, bar 1 was labeled with the S.T. and V.P. Apts, and then bar 2 was functionalized with cDNA-POSS-PQDs. When S.T. and V.P. were introduced, pathogen-Apt complexes would form and be released into the supernatant from bar 1. Under agitation, the two complexes reached bar 2 and subsequently reacted with cDNA-POSS-PQDs, which were immobilized on MXene. Then, the encoded probes would be detached from bar 2 to generate FL signals in the supernatant. Notably, the pathogens can resume their free state and initiate next cycle. They swim between the two bars, and the FL signals can be gradually enhanced to maximum after several cycles. The FL signals from released encoded probes can be used to detect the analytes. In particular, live pathogens can be distinguished from dead ones by using an assay. The detection limits and linear range for S.T. and V.P. were 30 and 10 CFU/mL and 10²–10⁶ CFU/mL, respectively. Therefore, this assay has broad application potential for simultaneous on-site detection of various live pathogenic bacteria in water.

在这项研究中，开发了一种荧光 (FL) 适体传感器，用于现场检测活的鼠伤寒沙门氏菌(ST) 和副溶血性弧菌（副总裁）。适体 (Apt) 功能化的多色多面体寡聚倍半硅氧烷-钙钛矿量子点 (cDNA-POSS-PQD) 的互补 DNA (cDNA) 用作编码探针，并结合双搅拌棒辅助信号放大进行病原体定量。在这个系统中，第 1 条用 ST 和 VP Apts 标记，然后第 2 条用 cDNA-POSS-PQD 功能化。当引入 ST 和 VP 时，病原体-Apt 复合物将形成并从第 1 条释放到上清液中。在搅拌下，这两种复合物到达第 2 条，随后与固定在 MXene 上的 cDNA-POSS-PQD 反应。然后，编码的探针将从第 2 条分离，以在上清液中产生 FL 信号。值得注意的是，病原体可以恢复其游离状态并启动下一个循环。他们在两个酒吧间游来游去，FL信号可以在几个循环后逐渐增强到最大。来自释放的编码探针的 FL 信号可用于检测分析物。特别是，活的病原体可以通过使用测定法与死的病原体区分开来。ST 和 VP 的检测限和线性范围分别为 30 和 10 CFU/mL 以及 10^分别为2 –10 ⁶  CFU/mL。因此，该测定法具有广泛的应用潜力，可以同时现场检测水中的各种活致病菌。