The aggregation and redispersion of positively-charged AuNPs ((+)AuNPs) modified with cysteamine (CS) could be regulated by the negatively charged As(III)-specific aptamer (As(III)-apt). In general, (+)AuNPs aggregated with increasing inducer concentration. However, in the present study, it was found that (+)AuNPs re-dispersed after a certain high concentration of As(III)-apt was reached. By optimizing the concentration of As(III)-apt that resulted in the aggregation and redispersion behavior of (+)AuNPs, a dual-mode colorimetric aptasensor for As(III) determination was established. It was not only able to quantify As(III) sensitively over a ranges of As(III) concentrations, but also to selectively differentiate As(III) and eliminate false results from other control ions by dual-mode.

用半胱胺 (CS) 修饰的带正电荷的 AuNPs ((+)AuNPs) 的聚集和再分散可以通过带负电荷的 As(III) 特异性适体 (As(III)-apt) 来调节。一般来说，(+)AuNPs 随着诱导剂浓度的增加而聚集。然而，在本研究中，发现 (+)AuNPs 在达到一定高浓度的 As(III)-apt 后会重新分散。通过优化导致 (+)AuNPs 聚集和再分散行为的 As(III)-apt 浓度，建立了用于 As(III) 测定的双模式比色适体传感器。它不仅能够在一系列 As(III) 浓度范围内灵敏地定量 As(III)，而且还可以选择性区分 As(III) 并通过双模式消除来自其他控制离子的错误结果。