Gold nanoparticle formation as an indicator of enzymatic methods: colorimetric L-phenylalanine determination.

ABSTRACT: An enzymatic-colorimetric method has been developed based on the reaction between L-phenylalanine (L-Phe) and the L-amino acid oxidase (LAAO) in the presence of Au(III), which has led to the formation of gold nanoparticles. The intensity of the localized surface plasmon resonance (LSPR) band of the generated nanoparticles (550 nm) can be related to the concentration of L-Phe in the sample. The mechanism of the LAAO-L-Phe enzyme reaction in the presence of Au(III) has been studied through the evaluation and optimization of experimental conditions. These studies have reinforced the hypothesis that the catalytic center of the enzyme helps the Au(III) reduction and, thanks to the protein, the Au⁰ form is stabilized as gold nanoparticles (AuNPs). In the calibration study, a sigmoidal

SUBMITTER: Martin-Barreiro A 

PROVIDER: S-EPMC8888390 | biostudies-literature | 2022 Mar

REPOSITORIES: biostudies-literature