Dithioerythritol functionalized gold nanoparticles-based fluorometric sensing of biogenic amines in food samples

Biogenic amines (BAs) provide information about the quality, freshness and toxicity of food products. Analysis of BAs in food such as meat, dairy products and fermented beverages is very important in terms of consumer health and product quality. In this study, a simple and sensitive nanoparticle-based fluorometric method has been developed in order to determine the total BA content of food samples. It is based on the measurement of fluo-rescence of the 1-alkylthio-2-alkyl-isoindole product formed from the reaction between OPA (o-phthalaldehyde) reagent with BA on the surface of gold nanoparticles (AuNPs) functionalized with the dithiol compound, 1,4-dithioerythritol (DTE), in alkaline medium. One thiol-S atom of DTE attached to AuNPs while the other thiol-S was free for the fluorogenic reaction among OPA, DTE and BA. The sensor was applied to aqueous standard solutions of histamine, tyramine, tryptamine, 2-phenylethylamine displaying a significant Stokes shift in their emission spectra (lambda(ex): 340 nm; lambda(em): 434-466 nm). The precision and accuracy were found by applying the standard addition procedure to food samples with known concentration of histamine. In the DTE-AuNP/OPA assay, detection limits of biogenic amines were found between 4.20 and 27.1 nM, lower than those of most absorptimetric and fluorometric BA sensors. The sensor was selective to BAs and has been successfully applied to some food samples (canned fish and wine). This nanosensor may have potential for the determination of BAs in regard to food quality and safety.

Automated summary

A simple and sensitive nanoparticle-based fluorometric method has been developed to determine the total content of biogenic amines in food samples. This method provides important information about the quality and safety of food products.