Ouyang Qin, Yang Yongcun, Ali Shujat, Wang Li, Li Huanhuan, 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.
Spectrochim Acta A Mol Biomol Spectrosc. 2021 Jul 5;255:119734. doi: 10.1016/j.saa.2021.119734. Epub 2021 Mar 23.
Staphylococcus aureus (S. aureus) is a pathogenic bacterium that seriously endangers food safety. Herein, a rapid, sensitive and specific aptasensor based on upconversion fluorescence resonance energy transfer (FRET) was developed for S. aureus detection in food. Aptamer-functionalized gold nanoparticles (AuNPs-aptamers) were bonded to cDNA-modified upconversion nanoparticles (UCNPs-cDNA) by complementary pairing, resulting in fluorescence quenching. After adding S. aureus into the system, the aptamers preferentially combined with S. aureus, dissociated UCNPs-cDNA from AuNPs-aptamers, and the fluorescence was recovered. Under optimized conditions, there was a significant linear correlation between fluorescence intensity and S. aureus concentration over the range 47-4.7 × 10 CFU/mL (R = 0.9904) with a detection limit of 10.7 CFU/mL. Furthermore, the precision and accuracy of the developed biosensor were validated using standard plate count method, yielding no significant differences. The proposed method has potential application for rapid and sensitive quantification of S. aureus in food.
金黄色葡萄球菌是一种严重危害食品安全的致病细菌。在此，开发了一种基于上转换荧光共振能量转移（FRET）的快速、灵敏且特异的适体传感器，用于食品中金黄色葡萄球菌的检测。适体功能化金纳米颗粒（AuNPs - 适体）通过互补配对与cDNA修饰的上转换纳米颗粒（UCNPs - cDNA）结合，导致荧光猝灭。向体系中加入金黄色葡萄球菌后，适体优先与金黄色葡萄球菌结合，使UCNPs - cDNA从AuNPs - 适体上解离，荧光恢复。在优化条件下，荧光强度与47 - 4.7×10 CFU/mL范围内的金黄色葡萄球菌浓度之间存在显著线性相关（R = 0.9904），检测限为10.7 CFU/mL。此外，使用标准平板计数法验证了所开发生物传感器的精密度和准确性，结果无显著差异。该方法在食品中金黄色葡萄球菌的快速灵敏定量方面具有潜在应用价值。
