Xiao Xueqian, Lu Ying, Zhang Jianxue, Ni Wei, Liu Junlin, Li Chaoqing, Yao Qunfeng, Sun Yujie, Zhang Guo-Jun, Zhang Yulin, Qin Yuqing, Zhou Yajuan
School of Laboratory Medicine, Hubei University of Chinese Medicine, Hubei Shizhen Laboratory, Wuhan 430065, China.
Department of Radiotherapy, Hubei Cancer Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Bioelectrochemistry. 2025 Dec;166:109046. doi: 10.1016/j.bioelechem.2025.109046. Epub 2025 Jul 9.
Nasopharyngeal carcinoma (NPC) is a highly malignant tumor, and early detection of biomarkers like miRNA-205 (miR-205) is critical for improving prognosis. However, accurate detection of miR-205 remains challenging due to its low abundance and matrix interference. Herein, an ultrasensitive electrochemical biosensor integrating Pt nanowires/MXene (PtNWs/MXene), rolling circle amplification (RCA), and CRISPR/Cas14a was developed for detecting exosomal miR-205. The dual characteristics of PtNWs/MXene (differential adsorption capacity for intact and cleaved DNA; HRP-like nanozyme activity) enable the conversion of the miR-205-triggered RCA-Cas14a cascade reaction into significant electrochemical signal changes. This biosensor eliminates the requirement for signal probe labeling of the electrode-modified DNA. Moreover, the enzyme-mimicking catalytic activity of PtNWs/MXene enables the catalysis of numerous 3,3',5,5'-tetramethylbenzidine (TMB) molecules, realizing a "one-to-many" signal amplification effect that significantly improves detection sensitivity. The biosensor achieves a detection limit of 4.6 aM (50 aM-10 pM linear range) and distinguishes single-base mismatches. Clinical validation confirmed its ability to differentiate NPC patients from healthy individuals, aligning with qRT-PCR results. By adjusting the RCA template, this strategy can be adapted for diverse RNA/DNA targets, offering a versatile platform for early disease diagnosis.
