Zhu Afang, Ali Shujat, Xu Yi, Ouyang Qin, Chen Quansheng
School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, PR China.
School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, PR China.
Biosens Bioelectron. 2021 Jan 15;172:112806. doi: 10.1016/j.bios.2020.112806. Epub 2020 Nov 8.
In this study, a sensitive biosensor was developed based on aptamer functionalized polydimethylsiloxane (PDMS) film for the detection of Staphylococcus aureus (S. aureus) using surface-enhanced Raman scattering (SERS) technology. Initially, the surface of PDMS film was chemically modified by piranha solution and 3-Aminopropyltriethoxysilane (APTES), and then AuNPs-PDMS film was prepared by coating gold nanoparticles (AuNPs) through electrostatic interaction. Next, the aptamers were immobilized on the AuNPs-PDMS membrane via gold-sulfur bond to form the capture substrate. Meanwhile, gold-silver core-shell nanoflowers (Au@Ag NFs) modified with mercaptobenzoic acid (4-MBA) and aptamers were applied as a signal probe. In the presence of the target, the signal molecular probe and the capturing substrate specifically combined with the target and resulted in a sandwich structure "capture substrate-target-signal molecular probe". Under the optimized experimental condition, the signal of 4-MBA at 1085 cm was linearly related to the S. aureus concentration in the range of 4.3 × 10 cfu mL-4.3 × 10 cfu mL (y = 326.91x-117.62, R = 0.9932) with a detection limit of 13 cfu mL. The method was successfully applied to spiked actual samples and a 92.5-110% recovery rate was achieved.
在本研究中，基于适体功能化聚二甲基硅氧烷（PDMS）薄膜开发了一种灵敏的生物传感器，用于利用表面增强拉曼散射（SERS）技术检测金黄色葡萄球菌（S. aureus）。首先，用王水和3-氨丙基三乙氧基硅烷（APTES）对PDMS薄膜表面进行化学修饰，然后通过静电相互作用包覆金纳米颗粒（AuNPs）制备AuNPs-PDMS薄膜。接下来，通过金硫键将适体固定在AuNPs-PDMS膜上形成捕获底物。同时，将用巯基苯甲酸（4-MBA）和适体修饰的金银核壳纳米花（Au@Ag NFs）用作信号探针。在目标物存在的情况下，信号分子探针与捕获底物与目标物特异性结合，形成“捕获底物-目标物-信号分子探针”的夹心结构。在优化的实验条件下，1085 cm处4-MBA的信号与金黄色葡萄球菌浓度在4.3×10 cfu mL-4.3×10 cfu mL范围内呈线性关系（y = 326.91x - 117.62，R = 0.9932），检测限为13 cfu mL。该方法成功应用于加标实际样品，回收率为92.5 - 110%。
