A novel tyramine biosensor based on carbon nanofibers, 1-butyl-3-methylimidazolium tetrafluoroborate and gold nanoparticles

A novel amperometric tyramine biosensor based on the immobilization of tyrosinase (Ty) onto glassy carbon electrode (GCE) modified with the carbon nanofibers (CNFs), chitosan (CH), ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate (IL) and gold nanoparticles (AuNPs) composite film was fabricated. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), cylic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques were performed to ensure the successful fabrication of the biosensor. Owing to the synergistic action of carbon nanofibers, gold nanoparticles and ionic liquid, the Ty/AuNPs/CNFs-IL-CH/GCE biosensor resulted in an accurate, practical, highly sensitive and selective analytical method for tyramine determination. Under optimal experimental conditions a linear working range of 2.0 x 10(-7) M to 4.8 x 10(-5) M, sensitivity of 176.6 mu A mM(-1) and detection limit of 9.3 x 10(-8) M were obtained. Moreover, the Ty/AuNPs/CNFs-IL-CH/GCE biosensor exhibited high selectivity towards tyramine in the presence of other biogenic amines. The applicability of the tyramine biosensor was demonstrated by detecting tyramine level in soy sauce sample with good recoveries.

Automated summary

A novel amperometric tyramine biosensor was fabricated by immobilizing tyrosinase on a glassy carbon electrode modified with a composite film of carbon nanofibers, chitosan, ionic liquid, and gold nanoparticles. The sensor showed high sensitivity and selectivity for tyramine detection, with a linear working range, sensitivity, and detection limit under optimal conditions. This biosensor also demonstrated good selectivity and applicability for detecting tyramine levels in soy sauce samples.