Doping ionic liquid into Prussian blue-multiwalled carbon nanotubes modified screen-printed electrode to enhance the nonenzymatic H2O2 sensing performance

Here we report the doping of ionic liquid (IL) into Prussian blue-multiwalled carbon nanotubes (PB-MWCNTs) modified screen-printed carbon electrodes (SPCE) to fabricate a nonenzymatic H2O2 sensor with enhanced analytical performance. The enzyme-free electrochemical sensor (Nafion-PB-MWCNTs/SPCE-IL) was prepared by home-printing the disposable carbon electrode using a 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4) doped commercial graphite-based ink, followed by drop-casting the synthesized cubic PB-MWCNTs hybrid and Nafion onto the sensing surface. Cyclic voltammetry and chronoamperometry were employed to comparatively characterize the features of sensors with and without IL doping for enzymeless H2O2 determination. The results demonstrate that the doping of [Bmim]BF4 can significantly improve the detection performance of the PB-MWCNTs modified SPCE for H2O2 monitoring, mainly due to the promoted electron transfer. It is found that, under optimized conditions, the fabricated sensor provides linear amperometric responses for H2O2 in the concentration range from 5 to 1645 μM, with a sensitivity of 0.436 mA cm−2 mM−1 and a detection limit of 0.35 μM (S/N = 3). In addition, the IL-doped electrode exhibits excellent selectivity, good reproducibility and favorable long-term stability for H2O2 detection. It is promising that the proposed H2O2 sensor can be used as an effective tool to measure the analyte in practical samples.