Abstract：Fibrous bioelectronic provides an intrinsically accessible platform for artificial nerve and real-time physiological perception. However, advanced fiber-based artificial synapse remains a challenge due to the contradictory conductance demands for brain-like energy consumption and ultrasensitive biomarker perception. Herein, taking advantage of the highly accessible surface, rich functional groups and excellent electrical conductivity, a hierarchical nanostructured MXene (Ti3C2Tx)-enabled artificial neurofiber was proposed for neuromorphic organic electrochemical transistors (OECT) with biomolecule-mediated plasticity. The device can successfully emulate the typical short-term/long-term synaptic behaviors in both protonic gel electrolyte and aprotic ionic liquid gel electrolyte, with a minimum energy consumption of 1.21 fJ/spike and 0.10 fJ/spike. Uric acid (UA), a neurocognitive function and acute joint pain involved biomarker, and its specific enzyme were investigated to simulate the neurotransmitter-receptor induced postsynaptic synaptic weight modulation and pain sensitization process. The OECT showed excellent sensitivity and anti-interference performance. Moreover, selective and concentration-depended synaptic behaviors were successfully achieved in both phosphate-buffered saline (PBS) and artificial urine environments with significant memory effects. This study provided a potential to combine artificial neuromorphic devices with biological sensory neural networks.