Minimal-Invasive Levodopa Sensing Based on Differential Amperometry Microneedle Electrodes Decorated with Spike-like Au Nanoparticles

摘要

Levodopa is the most commonly used drug for Parkinson's disease treatment since its inception. The concentration of levodopa must stay in a narrow range to achieve a better curative result which relies on the optimization of dosage. To adjust the dosage objectively and timely, it is of great significance to monitor the dynamic concentration of levodopa in Parkinson's patients. However, the high concentration of interferents coexist with levodopa can bring great inaccuracy to the detection. To address this issue, a novel high-accuracy levodopa biosensor based on differential amperometry microneedle electrodes is proposed. A pure levodopa signal can be extracted by two working electrodes with and without enzyme modification respectively. The result shows that this biosensor realize the dynamic detection of levodopa with the linear range of 0–20 µM, the sensitivity of 12.618 nA pM^{−1 cm−2, and the detection limit of 0.18 µM (S/N=3). The system has good anti-interference performance to detect levodopa in high concentration of uric acid, glucose, and ascorbic acid with a variation of less than 5% (n = 3).}