We developed a highly sensitive electrochemical detector with a micro-stirrer driven by surface acoustic waves (SAWs) for micro total analysis systems. The detector, fabricated on a LiNbO₃ wafer by microfabrication technology, consisted of a three-electrode system for electrochemical measurement and interdigital transducers (IDTs) for stirring the aqueous solution by SAWs. In an amperometry experiment with ferrocenecarboxylic acid and potassium phosphate buffer solution (total volume: 50 μL), the oxidation current was measured while the solution was stirred by SAWs generated by applying 1.4 W electric power to the IDTs. Under this condition, the oxidation current was about 13 times larger than that without SAW-stirring. Furthermore, the diffusion rate of analyte molecules evaluated by the Cottrell relation from amperometry measurements increased 12-fold by using the SAW micro-stirrer.

我们开发了一种高灵敏度的电化学检测器，该检测器带有一个由表面声波（SAW）驱动​​的微刺激器，用于微型总体分析系统。检测器，在LiNbO ₃上制造通过微细加工技术制成的硅片，由用于电化学测量的三电极系统和用于通过声表面波搅拌水溶液的叉指式换能器（IDT）组成。在使用二茂铁羧酸和磷酸钾缓冲溶液（总体积：50μL）的安培实验中，在溶液搅拌的同时测量氧化电流，该SAW是通过向IDT施加1.4 W电功率产生的SAW进行搅拌的。在这种条件下，氧化电流约为没有SAW搅拌的氧化电流的13倍。此外，通过使用SAW微型刺激器，通过安培法测量值通过Cottrell关系评估的分析物分子的扩散速率提高了12倍。