Construction of a novel fluorescent DNA aptasensor for the fast-response and sensitive detection of copper ions in industrial sewage.

Heavy metal pollution poses a great threat to the ecological environment and human health. In particular, copper ions (Cu) play a vital role in regulating fundamental life behavior, and the homeostasis of Cu is closely related to many physiological processes. The excessive accumulation of Cu in the human body through food and drinking water will cause severe diseases. However, current conventional Cu detection methods for evaluating the content of Cu are unable to meet the complete requirements of practical Cu analysis in the practical aquatic environment. In this work, we successfully constructed a novel fluorescent DNA aptasensor, which originated from the binding reaction between the improved DNA fluorescent light-up aptamer termed S2T3-GC and a small fluorescent molecule termed DFHBI-1T (S2T3-GC/DFHBI-1T) to realize fast and anti-interference response for Cu the competitive interaction between Cu and S2T3-GC (Cu/S2T3-GC) destroying the contained G-quadruplex structure of S2T3-GC. Moreover, it enables the sensitive detection of Cu with a detection limit of 0.3 μM and a wide detection linear range from 0.3 to 300 μM. Moreover, with the verification of high stability in real industrial sewage samples, this aptasensor exhibits excellent detection performance for Cu analysis in real water samples. Therefore, the proposed aptasensor exhibits great potential in exploring Cu-related environmental and ecological research.