A photoelectrochemical biosensor based on SnO2 nanoparticles for phosphatidylcholine detection in soybean oil

Abstract

A photoelectrochemical (PEC) biosensor based on SnO₂ nanoparticles (SnO₂ NPs) was developed and applied for phosphatidylcholine (PC) detection in soybean oil. SnO₂ NPs were grown on an indium tin oxide (ITO) electrode, polythionine (PTh) was electropolymerized on the surface of ITO/SnO₂ NPs, and choline oxidase (ChO_x) was immobilized to prepare the ITO/SnO₂ NPs/PTh/ChO_x electrode. The developed PEC biosensor can detect PC under visible light irradiation. The experimental conditions for PC detection were as follows: 1.8 mg mL⁻¹ ChO_x concentration, 0.5 V bias voltage, 18 mW cm⁻² light intensity, and pH 6. The PEC biosensor had a detection limit of 0.005 mM (S/N = 3) and a detection range from 0.03 mM to 4 mM. This PEC biosensor based on SnO₂ NPs was applied to detect PC in soybean oil. The recovery rate tested by the standard addition method was 95.2–107.4%. These findings were consistent with the results obtained by high-performance liquid chromatography (HPLC). Therefore, the proposed PEC biosensor based on SnO₂ NPs has excellent reproducibility, stability, and great potential applications in the PEC analysis of PC in soybean oil.