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 × 105µM), while exhibiting one of the lowest detection limits (8 × 10−2µM).