Institute of Microbial Technology (IMTECH), Council of Scientific and Industrial Research (CSIR), Chandigarh, 160036, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
Institute of Microbial Technology (IMTECH), Council of Scientific and Industrial Research (CSIR), Chandigarh, 160036, India.
Biosens Bioelectron. 2025 Jan 15;268:116872. doi: 10.1016/j.bios.2024.116872. Epub 2024 Oct 22.
Herein, we report a supersensitive and specific detection of Salmonella employing nanocatalysis of silver nanoparticle (AgNp). A nanobioprobe was developed employing specific antibody (Ab) that binds to a peptide present in transmembrane protein of Salmonella. We have studied 7 surface-exposed peptide hits from conserved virulence proteins (PagC, ST50, PagN, CdtB and FliC). These peptides were experimentally evaluated by BLI (Bio layer interferometry) for their reactivity towards antisera raised against an admix of major Salmonella serogroups. The most promising peptide was used to generate Ab with binding affinity Kd of 5.6 × 10 M. The Ab exhibited high specificity towards entire Salmonella serotypes prevalent in foods, as illustrated by FACS (Fluorescence-activated cell sorting) study. The Ab-AgNp probe was blocked with a dual layer to prevent non-specific interactions, confirmed by employing BLI and TEM (Transmission electron microscopy). For the electrochemical detection, the autonanocatalysis of AgNp in presence of HO was used to generate numerous Ag resulting in an amplified signal that could detect 10 cells/mL. The relative standard deviation (RSD) was observed to be 4.5%. The platform achieved recovery of 100-112% calculated for 10 cells/mL. The performance was validated in milk, buffer peptone water (BPW) and tap water by spiking studies. The study highlights the effectiveness of efficiently blocked AgNp-mediated probes for the highly selective and sensitive detection of Salmonella, representing a significant advancement in bacterial sensing.
在此，我们报告了一种基于银纳米粒子（AgNp）纳米催化的灵敏、特异检测沙门氏菌的方法。该方法利用与沙门氏菌跨膜蛋白中存在的肽结合的特异性抗体（Ab）开发了一种纳米生物探针。我们研究了 7 个来自保守毒力蛋白（PagC、ST50、PagN、CdtB 和 FliC）的表面暴露肽。通过生物层干涉（BLI）实验，这些肽针对针对多种沙门氏菌血清型的混合抗血清的反应性进行了实验评估。最有前途的肽被用于生成 Ab，其结合亲和力 Kd 为 5.6×10^-10 M。Ab 对食品中常见的整个沙门氏菌血清型表现出高度特异性，这一点通过流式细胞术（FACS）研究得到了证明。Ab-AgNp 探针被双层阻断以防止非特异性相互作用，这一点通过 BLI 和透射电子显微镜（TEM）得到了证实。对于电化学检测，在存在 HO 的情况下，AgNp 的自动纳米催化用于生成大量 Ag，从而产生可检测到 10 个细胞/mL 的放大信号。观察到相对标准偏差（RSD）为 4.5%。对于 10 个细胞/mL 的计算，该平台实现了 100-112%的回收率。通过加标研究在牛奶、缓冲蛋白胨水（BPW）和自来水中验证了该方法的性能。该研究强调了高效阻断的 AgNp 介导探针在高度选择性和灵敏检测沙门氏菌方面的有效性，代表了细菌感测方面的重大进展。
