A Duplex Specific Nuclease-Assisted Photoelectrochemical Biosensor Based on Mos2@Res2/Ti3c2 Hybrid for Ultrasensitive Detection of Colorectal Cancer-Related Pirna-31143

Abstract

PIWI-interacting RNAs (piRNAs) have attracted much attention in recent years due to their potential value as biomarkers, and piR-31143 has been identified as a potential biomarker for the diagnosis of colorectal cancer (CRC). However, the shortcomings of traditional detection approaches, such as complex operation and high cost, restrict their clinical application. In the present work, we reported a new photoelectrochemical (PEC) biosensor based on MoS2@ReS2/Ti3C2 hybrid for ultrasensitive detection of piRNA-31143 from human serum. Furthermore, a duplex specific nuclease-assisted signal amplification mechanism was introduced to improve the sensitivity of detection. The formation of the type-I heterostructure between MoS2 and ReS2 and the doping of Ti3C2 with excellent conductivity contributed to a significant photocurrent response. The presence of the piR-31143 triggered the chain displacement reaction and enzymatic cyclic amplification reaction on the electrode surface, leading to the collapse of the composite probe system. Consequently, the photocurrent of the PEC biosensor was proportional to the concentration of piR-31143. The linear detection range and calculated detection limit of the PEC biosensor were 10-1-106 fM and 0.023 fM, respectively. The stability of the photocurrent under 15 consecutive on-off irradiations (relative standard deviation of 1.17%) and the specific response to piR-31143 demonstrated the reliability of the PEC biosensor. Besides, the practicability of the PEC biosensor was verified by batch human serum detection. The area under the receiver operating characteristic curve to distinguish CRC patients from healthy controls was 0.942, demonstrating a promising avenue for the diagnosis of CRC patients.

Keywords: Photoelectrochemical sensor, Duplex specific nuclease, piRNA, MoS2@ReS2 heterostructure