Organic-inorganic hybrid matrix for electrochemical biosensing of tyrosine

The manuscript presents synthesis and application of organic-inorganic hybrid matrix, consisting of polypyrrole (PPy) and gold nanoparticles (AuNPs). The polypyrrole acts as conducting matrix and gold nanostructures play role of electro-catalysts. The composite of PPy-AuNPs was electrochemically synthesized on screen printed electrodes in single step and was characterized thoroughly using analytical techniques. The composite was used as matrix for immobilization of tyrosinase enzyme for tyrosine and catechin biosensing. The electrochemical measurements were performed using cyclic voltammetry (CV) and amperometry. For tyrosine, the composite based biosensor showed dynamic linearity from 10 to 100 nM, having sensitivity of 1.0 × 10−2 μAcm−2/nM, and LOD of 0.3 nM. For catechin, the dynamic linearity range was from 1 to 20 nM. The study showed that the biosensor exhibited more sensitivity towards tyrosine estimation as compared to catechin, which can be due to their structural difference. The biosensor was also used for sensing tyrosine and catechin in real samples and the study showed motivating results.