Fabrication of carbon nanotubes/poly(1,2-diaminobenzene) nanoporous composite via multipulse chronoamperometric electropolymerization process and its electrocatalytic property toward oxidation of NADH

A novel method was proposed for fabrication of a carbon nanotubes/poly(1,2-diaminobenzene) nanoporous composite based electrode. The poly(1,2-diaminobenzene) was deposited onto the surface of a glassy carbon electrode (GCE) modified with multi-wall carbon nanotubes (MWNTs) via multipulse chronoamperometric electropolymerization (MCE) process. Compared with the composite prepared by conventional electropolymerization (CE), the electronic and ionic transport capacity of the MCE-based composite were significantly improved due to its unique nanoporous structure. The surface of the composite-modified GCE was characterized with scanning electron microscopy (SEM) and cyclic voltammetry (CV). The nanoporous MCE-based electrode was applied to determination of NADH at a much low potential of 70 mV, and a linear range from 2.0 μM to 4.0 mM was observed with fast response (within 5 s) and a lower detection limit of 0.5 μM (based on S/N = 3). In comparison, a narrow linear range from 5.0 μM to 2.0 mM, slower response (up to 15 s) and a higher detection limit of 3.0 μM (based on S/N = 3) was obtained with the electrode prepared by CE. The wider linear range, lower detection limit and fast response of the MCE-based electrode implies that the new method proposed can provide more excellent platforms for sensitive electrochemical sensing and biosensing.