Chen Qingmei, Gao Ran, Jia Li
Ministry of Education Key Laboratory of Laser Life Science & Guangdong Provincial Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, 510631, China.
Ministry of Education Key Laboratory of Laser Life Science & Guangdong Provincial Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, 510631, China.
Talanta. 2021 Jan 1;221:121476. doi: 10.1016/j.talanta.2020.121476. Epub 2020 Aug 1.
A colorimetric aptasensor was developed for selective and sensitive detection of Salmonella typhimurium (S. typhimurium) based on the enhancement of bacteria for the peroxidase-like activity of dual aptamers modified bovine serum albumin stabilized-gold nanoclusters (aptamers@BSA-AuNCs). Micro-sized bacteria was found to be able to capture aptamers@BSA-AuNCs and 3,3',5,5'-tetramethylbenzidine (TMB), thus promoting the proximity of aptamers@BSA-AuNCs to TMB and greatly increasing the local concentrations of the enzyme-mimetic nanoparticles and their substrate. As a result, addition of bacteria promoted the formation of blue products in the catalytic system, which was utilized to achieve bacteria detection by colorimetry. The parameters influencing the colorimetric aptasensor were optimized by an orthogonal test. Under the selected conditions, the aptasensor exhibited a wide linear response to S. typhimurium in the concentration range of 10-10 cfu mL with a detection limit as low as 1 cfu mL. The feasibility of the aptasensor was verified by successful detection of S. typhimurium in egg samples with recoveries in the range of 92.4%-110%.
基于鼠伤寒沙门氏菌(S. typhimurium)对双适体修饰的牛血清白蛋白稳定金纳米簇(适体@BSA-AuNCs)类过氧化物酶活性的增强作用,开发了一种比色适体传感器,用于选择性和灵敏地检测鼠伤寒沙门氏菌。发现微米级细菌能够捕获适体@BSA-AuNCs和3,3',5,5'-四甲基联苯胺(TMB),从而促进适体@BSA-AuNCs与TMB的接近,大大提高了模拟酶纳米颗粒及其底物的局部浓度。结果,添加细菌促进了催化体系中蓝色产物的形成,利用这一点通过比色法实现细菌检测。通过正交试验对影响比色适体传感器的参数进行了优化。在选定条件下,该适体传感器对鼠伤寒沙门氏菌在浓度范围为10-10 cfu mL内呈现宽线性响应,检测限低至1 cfu mL。通过成功检测鸡蛋样品中的鼠伤寒沙门氏菌验证了该适体传感器的可行性,回收率在92.4%-110%范围内。