Villous 3D nanoconfined flexible carbon fibers-based electrode toward dopamine electrochemical detection

Flexible sensing interfaces for the analysis of biological samples are crucial to realize human dopamine health detection; thus, flexible sensors for biomolecular analysis have attracted considerable attention. Herein, we report a villous three-dimensional (3D) nanoconfined carbon fibers-based flexible sensor for the electrochemical analysis of dopamine (DA). Carbon nanofibers-modified carbon fibers (CNFs/CFs) with abundant nanochannels were obtained by chemical vapor deposition, and the sensing platform achieved ultra-sensitive analysis owing to the construction of nanoconfined spaces. The combination of a 3D network structure and surface N doping (N-CNFs/CFs) significantly enhanced the local enrichment of DA, thus providing a basis for ultrasensitive detection of DA. Furthermore, modified Au nanoparticles (Au/N-CNFs/CFs) exhibited s enhanced the electrocatalytic ability and electron transfer efficiency. The detection limit for DA reached 0.087 μM (S/N = 3) in the linear range of 1–800 μM. Under optimal conditions, the designed electrode material shows good performance in complex biological environments, including human serum, urine, and artificial cerebrospinal fluid). The developed Au/N-CNFs/CFs therefore provide a portable and efficient sensor for the clinical detection of biomolecules.