In this work, both electrochemical experiments and quantum chemical simulations were performed to explore an important topic namely the cetyl pyridinium bromide (CPB) modified carbon paste electrode (CPBMCPE) employed for detection of dopamine (DA) and uric acid (UA). The electrode was found to display excellent electrocatalysis and increased surface area for simultaneously detecting DA and UA via decreasing their oxidation overpotentials when compared to the bare electrode, demonstrating high selectivity and sensitivity. Although surfactants can increase carbon-electrode sensitivity for DA detection, its mechanism remains elusive. Here, we used quantum chemical models to tackle the interface at which sensing (electron transfer) takes place. Our computational results reveal that the charged cationic head of CPBs can offer an additional electron transfer site at the CPBMCPE interface such that the sensing ability of CPE is comparatively improved after the CPB modification. Such electrodes were also applied for sensing UA in a urine sample, reaching a satisfactory of recovery up to 98%. To comprehend, we also modeled the power of electron-accepting and donating of CPB with other commonly used cationic surfactants.

在这项工作中，进行了电化学实验和量子化学模拟，以探索一个重要的主题，即用于检测多巴胺（DA）和尿酸（UA）的十六烷基溴化吡啶鎓（CPB）改性碳糊电极（CPBMCPE）。与裸电极相比，发现该电极显示出出色的电催化性能，并增加了表面积，可通过降低DA和UA的氧化超电势同时检测DA和UA，证明了其高选择性和灵敏度。尽管表面活性剂可以增加DA探测的碳电极灵敏度，但其机理仍然难以捉摸。在这里，我们使用了量子化学模型来解决传感（电子转移）发生的界面。我们的计算结果表明，CPB的带电荷的阳离子头可在CPBMCPE界面处提供一个额外的电子转移位点，从而使CPB改性后CPE的感测能力得到相对提高。此类电极还用于感测尿液样品中的UA，回收率高达98％，令人满意。为了理解，我们还用其他常用的阳离子表面活性剂模拟了CPB的电子接受和供电能力。