基于核酸适配体修饰的纳米金双与门逻辑开关检测牛奶中的三聚氰胺和环丙氨嗪

通过使用适配体、十六烷基三甲基溴化铵（CTAB）、三聚氰胺和环丙氨嗪控制金纳米粒子的聚集和分散，设计了简单的双与门逻辑开关用来检测牛奶中的三聚氰胺和环丙氨嗪。首先，基于适配体T31与三聚氰胺的强特异性，通过CTAB的加入控制纳米金的聚集，制作了一个与门逻辑开关（AND logic gate 1）检测是否存在三聚氰胺。此逻辑开关用肉眼可识别的三聚氰胺检出限为0.24 mg·L-1，借助分光光度计的检出限(LOD)为85 μg·L-1。根据适配体Tcy1与环丙氨嗪的强特异性，通过CTAB的加入控制纳米金的聚集，设计了与门逻辑开关（AND logic gate 2）。此逻辑开关用肉眼可识别的检出限为0.17 mg·L-1，借助分光光度计的检出限(LOD)为9.0 μg·L-1。因此，通过这一逻辑开关组可以实现牛奶中三聚氰胺和环丙氨嗪的快速检测。

Detection of Melamine and Cyromazine in Raw Milk by Aptamer-Facilitated Gold Nanoparticle-Based Logic Gates

In this paper, we developed a simple design and a detection method for AND logic gates by using aptamers, Cetyltrimethyl Ammonium Bromide (CTAB), and melamine and cyromazine to control the aggregation and dispersion of gold nanoparticles (AuNPs). First, Based on the fact that aptamer T31 can specifically bind with melamine, and CTAB immediately resulted in the aggregation of AuNPs, an AND gate was fabricated to find whether there was melamine. It also has a detection limit of 0.24 mg·L-1 by the naked eye to detect melamine, and the limit of detection (LOD) by a spectrophotometer is 85 μg·L-1. Second, with the adsorption of aptamer Tcy1 on AuNPs and the strong coordination of Tcy1 with cyromazine, the addition of cyromazine and CTAB immediately resulted in the aggregation of AuNPs, giving rise to another AND gate. It also has a detection limit of 0.17 mg·L-1 by the naked eye, and the limit of detection (LOD) is 9.0 μg·L-1 by spectrophotometer. So, these logic gates can be used to detect melamine and cyromazine in raw milk.