MXene-MoS2 carbon-fiber-based flexible electrochemical interface for multiple bioanalysis in biofluids

Flexible sensing technology has received widespread attention in the monitoring of human physiological indicators. Thus, it is of great significance to develop a universal flexible sensing interface for early diagnosis of multi-level biomarkers. Herein, we reported a multifunctional 3D carbon fiber paper (CFP)-MXene-MoS2 (CMM) sensing interface, which provided a flexible electrochemical biosensing platform for the ultrasensitive detection of multiple bioanalysis in biofluids. Notably, the CMM electrochemical interface was comprised of staggered carbon fibers on which the organ-like MXene-MoS2 heterostructure covered with MoS2 nanosheet arrays was uniformly allocated, permitting local enrichment of biomolecules for enhanced biomolecular capture efficiency, laying a solid foundation for the ultrasensitive detection of multiple biomolecules. In proof-of-concept experiments, we validated that the flexible CMM interface could be applied for ultrasensitive analyzing of quite a few biomolecules like ascorbic acid (AA), uric acid (UA), dopamine (DA) and microRNA (miRNA), with charming sensitivity and reproducibility. It was worth mentioned that an ultra-high sensitivity of 3.16 aM was acquired towards detecting microRNA. Under optimal parameters, the designed electrochemical interface worked well in complex biofluids such as human serum and urine samples. Overall, this flexible and disposable CMM interface with ultrahigh sensitivity provided insights for a more portable, accessible and valuable approach for monitoring biomolecules in clinical diagnosis.