Application of Cu/porous silicon nanocomposite screen printed sensor for the determination of formaldehyde

•Decreasing the overpotential of formaldehyde oxidation on CuNPs/PS about 700 mV.•Significant reduction of CO poisoning of electrode in formaldehyde oxidation process.•Modification of SPCE with Cu/PS nanostructure to construct a sensitive and selective formaldehyde sensor.•Amperometric detection of formaldehyde in water samples using CuNPs/PS/SPCE.•The response of designed sensor is very fast, reproducible and stable.•Due to oxidation of formaldehyde on less positive potentials, there is no significant interference on amperometric detection of analyte. The copper–porous silicon (Cu/PS) nanostructure was synthesized by loading copper nanoparticles (CuNPs) on the etched PS through electroless deposition and characterized by various techniques. The electrocatalytic activity of the Cu/PS nanostructure modified screen printed carbon electrode (SPCE) was investigated for the electro oxidation of formaldehyde in alkaline media using cyclic voltammetry (CV). The modified electrode exhibits unique electrocatalytic activity for the oxidation of formaldehyde through an Electrochemical-Chemical (EC') pathway with 700 mV anodic shift toward negative potentials. Based on these results, a novel screen printed sensor for the determination of formaldehyde was developed. Due to oxidation of formaldehyde at very negative potentials, the hydrodynamic amperometric response of constructed nanosensor is very selective and linear from 0.4 mM to 4 mM of formaldehyde. The detection limit of amperometric method is 0.0124 µM. The catalytic response of proposed CuNPs/PS/SPCE for the oxidation of formaldehyde is very fast (less than 3 s), reproducible and stable. It was successfully applied as a new working electrode in amperometric determination of formaldehyde in water samples. This electrode can be used as a miniaturized sensor for the detection of formaldehyde at low concentrations. [Display omitted]