OPTIMIZATION OF NEWLY FABRICATED LACCASE BIOSENSOR BASED ON SINGLE-WALLED CARBON NANOTUBE FOR TYRAMINE DETECTION

Abstract

Tyramine (TYR), also identified as 4-(2-aminoethyl) phenol, is an organic compound. Its elevated presence indicates prolonged food storage, leading to spoilage and potentially impacting human well-being. To address this concern, a biosensor was designed on a single-walled carbon nanotube carboxyl-functionalized screen-printed carbon electrode (COOH-SWCNT-SPCE). Laccase (LAC)-based electrochemical biosensors were effectively created using a simple and innovative technique involving enzyme LAC being drop cast. Electrochemical Impedance Spectroscopy (EIS), Cyclic Voltammetry (CV), and Differential Pulse Voltammetry (DPV) were utilized to assess the properties and electrochemical behavior of the modified SPCEs. Under optimal experimental conditions, the LAC/COOH-SWCNT-SPCE biosensor exhibited favorable performance at scan rates of 50 mV s-1 (within the range of 10 to 500 mV s-1), pH 8.0 (ranging from 7.0 to 10.0), 4 µL enzyme LAC (varying from 2 to 10 µL), and 1.0 mg mL-1 SWCNTs (ranging from 0.2 to 3.0 mg mL-1). Deposition potential and time were set at 0.5 V. The modified SPCEs demonstrated effective usage for TYR measurement, achieving a Correlation Coefficient (R2) of 0.981 and a Limit of Detection (LOD) of 0.070 mM.