Photoresponsive Electrochemical DNA Biosensors Achieving Various Dynamic Ranges by Using Only-One Capture Probe.

The rational design of DNA capture probes for modulating the binding affinity to tune the dynamic range of electrochemical DNA (E-DNA) biosensors is valuable and effective. Most of current strategies, however, require designing several DNA capture probes to achieve the tunable dynamic range, which is cumbersome and costly. Herein, we develop the photoresponsive E-DNA biosensors with tunable dynamic ranges by using only one photocleavable capture probe (PC-CP). The photoresponsive PC-CP is a stem-loop DNA structure containing a photocleavable linker (PC-linker) in the loop. The PC-linker can be cleaved by UV irradiation to switch the structure of PC-CP, through which the binding affinity to the target could be tuned. In this way, the dynamic range, the sensitivity, and the specificity of photoresponsive E-DNA biosensors can be tuned. Furthermore, the developed photoresponsive E-DNA biosensors enable sensitive and selective detection of target DNA in complex samples with a tunable dynamic range, which offers the possibility of clinical applications.