Biosensor with Nano‐gold Particle Modified Pencil Lead Carbon Electrode for Long‐term Glucose Monitoring of Waste Tree Branch Hydrolysis

Abstract

AbstractA 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 μA mM‐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 of measurement for this method 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.