In this communication, sphingomyelin (SM) in the plasma membrane of single cells is detected electrochemically using an enzyme-modified Pt microelectrode for the first time. The enzymes immobilized at the electrode surface, which include sphingomyelinase (SMase), alkaline phosphatase (ALP), and choline oxidase, react with SM in a series of reactions to generate hydrogen peroxide. The electrochemical oxidation of hydrogen peroxide induces an elevation in the current, which offers a quantitative determination of SM in a range from 140 to 560 µM. Further contact of the microelectrode with one oocyte cell results in the reaction of SM in the plasma membrane with the enzymes at the electrode. The resulting current increase is correlated with the content of SM in the plasma membrane, confirming the electrochemical detection of membrane SM in single cells. This success in single cell electrochemical analysis of membrane SM expands the application of microelectrodes in single cell studies, which will help in the elucidation of cellular heterogeneity in lipid trafficking.

在这种交流中，首次使用酶修饰的Pt微电极以电化学方式检测单细胞质膜中的鞘磷脂（SM）。固定在电极表面的酶包括鞘磷脂酶（SMase），碱性磷酸酶（ALP）和胆碱氧化酶，在一系列反应中与SM反应生成过氧化氢。过氧化氢的电化学氧化导致电流升高，从而可定量测定140至560 µM的SM。微电极与一个卵母细胞的进一步接触导致质膜中的SM与电极上的酶发生反应。电流的增加与质膜中SM的含量相关，证实了单细胞膜SM的电化学检测。膜SM的单细胞电化学分析的成功扩展了微电极在单细胞研究中的应用，这将有助于阐明脂质运输中的细胞异质性。