Development of an on-line sensing system of catecholamines and its application for medical use

研制了一种用于人工心脏控制的能实时测量和反馈儿茶酚胺浓度的电化学传感器系统，采用碳纤维工作电极、Ag-AgCl参比电极和恒电位仪进行了电化学分析。在模拟循环系统中，肾上腺素和去甲肾上腺素的最低可检测浓度约为1-2 ng/ml（10 μ <-8>mol/l）。利用这种结构的人工心脏控制系统，尽管当将传感器置于山羊血浆而不是磷酸盐缓冲溶液中时，由于各种物质如血浆蛋白质吸附在电极上，传感器的灵敏度降低，但没有延迟，表现出令人满意的性能。 ...更多信息 因此，使用技术以防止血液蛋白质吸附到电极上。将透析溶液冲洗通过用于透析的纤维素微管（截留分子量=50000）;将微管浸入山羊血浆中，并使用上述电化学检测器测量透析溶液中的儿茶酚胺浓度。利用该系统，当透析溶液的流速为10 ml/min时，透析溶液中的儿茶酚胺浓度与血浆中的儿茶酚胺浓度之间的比率约为20%，具有约90秒的时间延迟。血浆肾上腺素和去甲肾上腺素的最低检测浓度均为10 μ mol/l<-7>;可以根据血浆中的儿茶酚胺浓度变化的算法来改变驱动条件。作者目前正在尝试：1）将电极和透析系统合并到一个微传感器系统中，2）将传感器的灵敏度提高到10 μ <-9>mol/l。少

An electrochemical sensor system was developed which allows real-time measurement and feedback of catecholamine concentrations, and which can be used in the control of artificial hearts.Electrochemical analyzes were carried out using a carbon fiber working electrode, an Ag-AgCl reference electrode, and a potentiostat. The operating parameters of the pneumatically-driven artificial heart system were altered in accordance with the algorithm for changes in the catecholamine concentration.The minimum detectable concentrations of both adrenaline and noradrenaline in a mock circulatory system using a phosphate-buffered solution were approximately 1-2 ng/ml (10^<-8> mol/l). An artificial heart control system utilizing this arrangement performed satisfactorily without delay although the sensitivity of the sensor decreased when placed in goat plasma instead of phosphate-buffered solution, due to the adsorption on to the electrodes of various substances such as plasma proteins.A microdialysis te … More chnique was therefore used in order to prevent blood proteins from being adsorbed on to the electrods. The dialytic solution was flushed through a cellulose microtube (cut-off molecular weight=50000) for dialysis ; the microtube was immersed in the goat plasma, and the catecholamine concentrations in the dialytic solution were measured using the above electrochemical detector. With this system, the ratio between catecholamine concentrations in the dialytic solution and that in the plasma was approximately 20% when the flow rate of the dialytic solution was 10 ml/min, with a time delay of approximately 90 seconds. Using this system, the minimum detectable concentration of both plasma adrenaline and noradrenaline was 10^<-7> mol/l ; it was possible to alter the driving conditions in accordance with the algorithm for changes in the catecholamine concentration of the plasma. The authors are currently attempting to : 1)incorporate the electrodes and the dialytic system into one microsensor system, and 2)improve the sensitivity of the sensor to 10^<-9> mol/l. Less