Ultrawide-Range Electrochemical Biosensing Using Electrospun Carbon Nanofibers With High Density of States

We show that electrochemical sensors based on continuous and interconnected electrospun carbon nanofibers with high density of states (DOS) can achieve controlled increase in their electroactive surface areas (ESAs), and thus a dramatic expansion of electrochemical sensing ranges while maintaining high sensitivity. These high-DOS electrospun carbon nanofibers (HD-ECNFs) with excellent electrocatalytic activities can be obtained through optimization of carbonization conditions. The ESAs of the HD-ECNF sensors can be easily manipulated by adjusting deposition time during electrospinning. Dopamine (DA), an important neurotransmitter, is used as the model analyte to evaluate the performance of the HD-ECNF sensor. Compared to previously-reported CNT- and graphene- based electrochemical sensors for DA detection, the HD-ECNF sensor developed here can achieve a remarkably wider detection range, spanning more than six orders of magnitude (from 2 × 10⁻¹ to 7 × 10⁵ µM), while exhibiting one of the lowest detection limits (8 × 10⁻² µM).