Protein denaturation inspired microchannel-based electrochemiluminescence sensor for formaldehyde detection

Abstract

Establishing an effective system to measure formaldehyde (HCHO) content in food is of great significance due to food safety concern. Inspired by the mechanism of HCHO-induced protein denaturation and its effect on ion/molecule transport in nanochannels, a bioinspired microchannel-based electrochemiluminescence (ECL) sensor was constructed for HCHO detection. Benefiting from the water solubility of HCHO, the molecules rapidly spread and enriched at the ethylenediamine (EDA) functionalized microchannel interface. The reaction between EDA and HCHO significantly increased the negative charge density, leading to enhanced electroosmotic flow (EOF). This enhancement resulted in ion concentration depletion at the microchannel tip and a corresponding decrease in ionic current and ECL intensity. The ECL intensity exhibited a linear dependence on the logarithm of HCHO concentration ranging from 1 pg mL⁻¹ to 100 ng mL⁻¹, with a detection limit of 0.26 pg mL⁻¹(S/N = 3). The biosensor demonstrated high selectivity, successfully detecting HCHO in shrimp samples. The performance of the bioinspired sensor was confirmed through comparation with existing methods, showcasing its superior sensitivity and reliability. The bioinspired sensor provides robust technical support for HCHO detection, crucial for food safety monitoring. Additionally, the innovative combination of bionics and microchannel-based ECL technology broadens the application range of ECL sensors, marking a significant advancement in the field.