Department of Chemistry, Gachon University, Seongnam-daero 1342, Sujeong-gu, Seongnam-si, Gyeonggi-do, 13120, Republic of Korea.
Department of Chemistry, Gachon University, Seongnam-daero 1342, Sujeong-gu, Seongnam-si, Gyeonggi-do, 13120, Republic of Korea.
Anal Biochem. 2022 May 15;645:114634. doi: 10.1016/j.ab.2022.114634. Epub 2022 Mar 8.
An ultrasensitive colorimetric aptasensor for the detection of amoxicillin (AMO) based on the Tris-HCl buffer-induced aggregation of gold nanoparticles (AuNPs) was developed. The AuNPs were aggregated by the addition of Tris-HCl buffer. The adsorption of the aptamer on the AuNP surface increased its negative charge density, leading to the enhancement of the electrostatic repulsion between the nanoparticles, thus protecting AuNPs from aggregation in the Tris-HCl buffer. However, the specific binding of the aptamer with AMO induced conformational changes in the aptamer, which reduced the adsorption of the aptamer on the AuNP surface, diminishing the protective effect of the aptamer. This resulted in the aggregation of AuNPs by Tris-HCl buffer, and consequently, color change of the solution containing AuNPs from red to blue. Under optimized conditions, a linear relationship between the absorbance ratio variation (ΔA/A) and the AMO concentration was observed in the concentration range of 0.1-125 nM, with a detection limit of 67 pM. The developed biosensor exhibited high selectivity toward AMO. Moreover, this strategy was successfully applied to the detection of AMO in lake water samples. Thus, the present aptasensor is a promising alternative for the simple and ultrasensitive detection of AMO in the environment.
基于 Tris-HCl 缓冲液诱导金纳米粒子 (AuNPs) 聚集的原理，开发了一种用于检测阿莫西林 (AMO) 的超灵敏比色适体传感器。加入 Tris-HCl 缓冲液后，AuNPs 发生聚集。由于适体在 AuNP 表面的吸附增加了其负电荷密度，导致纳米粒子之间的静电斥力增强，从而保护 AuNPs 在 Tris-HCl 缓冲液中不发生聚集。然而，适体与 AMO 的特异性结合会导致适体构象发生变化，从而减少适体在 AuNP 表面的吸附，降低适体的保护作用。这导致 AuNPs 在 Tris-HCl 缓冲液中发生聚集，从而使含有 AuNPs 的溶液颜色从红色变为蓝色。在优化条件下，在 0.1-125 nM 的浓度范围内，吸光度比值变化 (ΔA/A) 与 AMO 浓度之间呈现线性关系，检测限为 67 pM。所开发的生物传感器对 AMO 具有高选择性。此外，该策略还成功应用于湖水样品中 AMO 的检测。因此，本适体传感器为环境中 AMO 的简单、超灵敏检测提供了一种有前途的替代方法。
