In this study, chitosan-based polyurethane (PU) membrane modified electrodes were prepared for sensitive, practical and fast measurement of α-lipoic acid (ALA), which is an important biomolecule. PU membranes were synthesized using hexamethylene diisocyanate, chitosan, caffeic acid and polyethylene glycol compounds. Chemical structure, thermal stability and morphological properties of the prepared PU membranes were determined with different instrumental techniques. Surface morphology, wettability and hydrophilicity of synthesized chitosan-based PU membranes were investigated. Gold electrode was modified by these PU membranes with different film thicknesses. The bare and PU membrane coated electrodes were used for deduction of ALA by cyclic voltammetry, differential pulse voltammetry and amperometry techniques. In addition, sensitivity, linearity, repeatability and deduction limit of PU modified electrodes were investigated. Modified electrodes showed wide linear detection range (5–200 µmolL⁻¹), low detection limit (4.931 µmolL^-1) and short response time. Results show that polyurethane modified electrodes are good alternative for ALA determination.

在这项研究中，制备了壳聚糖基聚氨酯 (PU) 膜修饰电极，用于灵敏、实用和快速测量 α-硫辛酸 (ALA)，这是一种重要的生物分子。PU 膜是使用六亚甲基二异氰酸酯、壳聚糖、咖啡酸和聚乙二醇化合物合成的。用不同的仪器技术测定了制备的 PU 膜的化学结构、热稳定性和形态特性。研究了合成的壳聚糖基聚氨酯膜的表面形态、润湿性和亲水性。这些不同膜厚的 PU 膜对金电极进行了修饰。通过循环伏安法、差分脉冲伏安法和电流法技术，将裸电极和 PU 膜涂层电极用于推算 ALA。此外，灵敏度、线性、研究了PU改性电极的重复性和扣除限度。改良电极显示出较宽的线性检测范围 (5–200 µmolL⁻¹ )、检测限低 (4.931 µmolL ^-1 ) 和响应时间短。结果表明，聚氨酯改性电极是 ALA 测定的良好替代品。