Biosensor with nano-gold particle modified pencil lead carbon electrode for long-term glucose monitoring of waste tree branch hydrolysis

Abstract

A new type electrode was formed by modifying a pencil lead with carbon paste and glucose oxidaselinked nano-gold particles. The cyclic voltammetric oxidative potential for glucose measurement with the mediator hydroxymethylferrocene was at 0.33 V. During a 45-day period, the glucose standard addition calibration curve exhibited a wide linear concentration range (0-33.41 mM) accompanied with good linearity (r2 ≥ 0.9985); the sensitivity of the electrode was larger than 5.00 μAmM-1 and the limit of detection (LOD) was below 22.3 μM. This glucose sensor electrode was also usable 228 days later. Mannose, galactose and xylitol produced 5-8% interference and cellobiose, xylose, and arabinose gave 0-1% interference. The glucose produced from the waste Cinnamomum caphora tree branch fiber hydrolysis was successively analyzed by the electrode for 4 days. The analysis accuracy of the electrode method by the spike experiment was up to 98.6% and the precision ofmeasurement for thismethod was below 5.3%. The glucose content in the immobilized enzyme hydrolysate of the waste tree branches by the electrode method was comparable to that of the HPLC method.