Nano Electrochemistry Laboratory, College of Engineering, University of Georgia, Athens, Georgia 30602, USA.
Analyst. 2013 Nov 7;138(21):6623-31. doi: 10.1039/c3an01295f.
Electrochemical sensing of methyl salicylate, a key plant volatile has been achieved using a gold nanoparticle (AuNP) modified screen printed carbon electrode (SPCE). The electrochemical response of planar gold electrodes, SPCE and AuNP-SPCE in alkaline electrolyte in the presence and absence of methyl salicylate were studied to understand the amperometric response of various electrochemical reactions. The reaction mechanism includes hydrolysis of methyl salicylate and the oxidation of negative species. The electrochemical responses were recorded using cyclic voltammetry and differential pulse voltammetry techniques, where the results showed characteristic signals for methyl salicylate oxidation. Among the examined electrodes, AuNP-SPCE possessed three fold better sensitivity than planar gold and 35 times better sensitivity than SPCE (at 0.5 V). The methyl salicylate sensing by AuNP-SPCE possessed <5% variation coefficient for repeatability, one week of stable performance with no more than 15% activity loss even if used multiple times (n = 8). Even in the presence of high concentration of interfering compounds such as cis-3-hexenol, hexyl acetate and cis-hexenyl acetate, AuNP-SPCE retained >95% of its methyl salicylate response. The electroanalytical results of soybean extract showed that AuNP-SPCE can be employed for the determination of methyl salicylate in real samples.
使用金纳米粒子（AuNP）修饰的丝网印刷碳电极（SPCE）实现了水杨酸甲酯的电化学传感，水杨酸甲酯是一种关键的植物挥发性物质。研究了平面金电极、SPCE 和 AuNP-SPCE 在碱性电解质中存在和不存在水杨酸甲酯时的电化学响应，以了解各种电化学反应的安培响应。反应机制包括水杨酸甲酯的水解和负物种的氧化。使用循环伏安法和差分脉冲伏安法技术记录电化学响应，结果显示出水杨酸甲酯氧化的特征信号。在所检查的电极中，AuNP-SPCE 的灵敏度比平面金高 3 倍，比 SPCE 高 35 倍（在 0.5 V 时）。AuNP-SPCE 对水杨酸甲酯的传感具有 <5%的重复性变异系数，即使多次使用（n = 8），其稳定性也可保持一周以上，活性损失不超过 15%。即使存在高浓度的干扰化合物，如顺-3-己烯醇、乙酸己酯和顺-己烯基乙酸酯，AuNP-SPCE 仍保留其水杨酸甲酯响应的>95%。大豆提取物的电化学分析结果表明，AuNP-SPCE 可用于实际样品中水杨酸甲酯的测定。
