A Sensitive Electrochemical Sensor for the Detection of Formaldehyde Based on L-Alanine/Pt-Nanoparticles Modified Glassy Carbon Electrode

A novel and sensitive electrochemical sensor for the detection of formaldehyde based on the platinum nanoparticles (Pt-NPs) and L-alanine modified glassy carbon electrode was developed by electrodeposition and self-assembly methods at room temperature. The structure and morphologies of the L-alanine/PtNPs sheets were characterized by SEM. The electrochemical behaviours of formaldehyde at the modified electrode in alkaline media was investigated through cyclic voltmmetry and chronoamperometry and the influence of scanning speed and the type and acidity of electrolytes, etc. conditions on the catalytic oxidation of formaldehyde was discussed. Results showed that the modified sensor had a strong electro-catalytic activity for the oxidation of formaldehyde. The oxidation peak current of formaldehyde was linear to concentrations in the range of 0.3 to 1050 mu mol/L, with the low detection limit of 0.14 mu M (S/N = 3) and the recovery got by standard addition method was in the range of 95.6 to 103.2 %. The synergy effect of Pt nanoparticles and L-alanine contributed to the excellent electrochemical response towards the formaldehyde oxidation. The modified sensor we prepared exhibited higher sensitivity, broader linear range, lower detection limit, more excellent stability as well as good selectivity for the determination of formaldehyde.