Development of a Novel Label-Free NIR Aptasensor Based on Triphenylmethane Dyes for Rapid and Sensitive Detection of Copper Ion

Abstract

Heavy metal pollution in nature poses a serious threat to the ecological environment and human health, however, due to the reliance on expensive equipment, labor-intensive sample preparation, and skilled operation, traditional copper ion analysis techniques hinder their application in the field and in real time. In this work, we report a novel near-infrared aptamer sensor (NIRApt) that originates from the binding reaction between the DNA aptamer AptCu and fluorescent small molecule CV, and enables rapid detection of Cu2+ through the competitive effect of Cu2+ with AptCu. This candidate exhibits significant near-infrared fluorescence enhancement after aptamer binding. NIRApt exhibits superior performance, requiring only three core components to achieve a fast response time and operational simplicity of less than a minute. The sensor shows high sensitivity with a detection limit as low as 61 nM, making it suitable for the detection of trace amounts of Cu2+ in diverse samples. The efficacy of NIRApt has been validated through successful applications in real water samples, highlighting its potential for environmental monitoring, contamination assessment and remediation.