Nanoporous carbon-fiber microelectrodes for sensitive detection of H2O2 and dopamine

In this study, sensitive electrochemical detection of H2O2 and dopamine (DA) was demonstrated using a nanoporous carbon fiber electrode (CFE). SEM images confirmed the surface modification and elemental composition analysis demonstrated an increase in the C/O ratio favoring higher conductivity and electron-transfer rate. Nanoporous CFEs were first used for electrochemical oxidation and reduction of H2O2 and results were compared with those of unmodified CFEs. Oxidation current drastically increased with heat treatment and unlike unmodified CFEs, nanoporous CFEs demonstrated a concentration-dependent current change for the reduction of H2O2. Next, the performance of nanoporous CFEs was assessed for DA detection in comparison to unmodified CFEs and they showed remarkable electrocatalytic activity in terms of both sensitivity and selectivity. The nanoporous CFEs have great potential to be used in various applications ranging from measurements in localized volumes to tissue analysis. •Heat-treatment was used to render CFE surface nanoporous.•Nanoporous CFE demonstrated high electrocatalytic activity for the detection of H2O2 in comparison to unmodified CFE.•Nanoporous CFE demonstrated a concentration-dependent current change for the reduction of H2O2 unlike unmodified CFEs.•Nanoporous CFE showed remarkable response for the detection of DA in terms of both sensitivity and selectivity.