Flexible Fiber Electrodes Based on Fe–BiVO4/BiOCl/FeOOH Nanocomposites for the Photoelectrochemical Detection of Dopamine

Dopamine (DA) abnormality is closely linked to Parkinson’s and other neurodegenerative diseases. Establishing a sensitive and highly selective DA detection platform holds significant importance for clinical diagnosis and disease prevention. This study successfully prepared Fe–BiVO 4 /BiOCl-CF/FeOOH flexible composite electrode based on carbon fiber fabric (CF) substrates via electrospinning, hydrothermal synthesis and impregnation-in situ growth methods. Corresponding photoelectrochemical (PEC) sensors were constructed for quantitative DA detection. The Fe–BiVO 4 /BiOCl heterojunction significantly suppressed photogenerated carrier recombination. FeOOH, functioning as the hole transport layer, further optimized charge separation efficiency, while the three-dimensional porous structure of CF shortened the electron transport path and reduced electrical resistance. The constructed PEC sensor exhibits favorable sensing performance for DA in 0.1 M phosphate buffer (pH = 7.0). Within the concentration range of 1–40 μM, the photocurrent response shows an excellent linear correlation with DA concentration (R 2  = 0.99446), and the detection limit is determined to be 0.038 μM (3σ/S). Moreover, the sensor exhibits negligible interference from common coexisting substances and retains over 80% of its initial photocurrent efficiency after 11 days of continuous operation, demonstrating satisfactory selectivity and stability. This work provides a feasible strategy for constructing highly sensitive, portable PEC sensors for DA detection. Graphical