Amperometric biosensor based on synthesised laccase nanoparticles covalently anchored onto gold electrode for phenol quantification in real samples

Phenolic compounds impact human health and the environment in both beneficial and undesirable manners. While some phenols are known to be antioxidants, others function as hormones or neurotransmitters, some are significant environmental contaminants, and others have the potential to cause cancer or disturb the endocrine system. To track the amount of toxicity, it is essential to identify and measure these phenols in food, the environment, and human samples. A novel phenol sensing amperometric enzymatic biosensor with a gold electrode was fabricated based on covalent immobilisation of synthesised laccase nanoparticles (LacNPs). The process of synthesising laccase nanoparticles was examined using UV–visible spectrophotometry, FTIR, transmission electron microscopy, zeta potential, and dynamic light scattering techniques. For analysis of electrode fabrication (LacNPs-AuE), scanning electron microscopy, cyclic voltammetry, and electrochemical impedance spectra including Nyquist plots and Bode’s plot were examined. Optimisation and evaluation of fabricated biosensor were investigated using cyclic voltammetry studies. The LacNPs-AuE biosensor’s overall characteristics were enhanced by the direct immobilisation of laccase nanoparticles, enabling the analysis at a lower detection limit (0.3 μM), wider linear range (0.1–100 μM and 100 to 600 μM), faster response time (3 s), and high recovery (92–98%). Tea, alcohol, and pharmaceutical samples were tested for total phenolic content using the biosensor; the results were compared with spectrophotometric data.