Bio-affinity Chemical Sensors for in Vivo Monitoring of Bio-active Substances

本研究的目的是建立一种能够检测脑内影响神经元活动的内源性化学物质的生物传感系统。为此，我们研究了以下传感器的特性：（1）酶微透析传感器和（2）用于免疫吸附测定的石英晶体微天平传感器.酶微透析生物传感器同心圆型生物传感器由玻璃体、工作电极和用于灌注酶溶液的进、出口毛细管组成，玻璃体顶端有一层半透膜。将工作电极和入口毛细管插入到半渗透性中空纤维（o.d.= 220 μm）。该传感器的优点是可以通过灌注酶溶液来改变工作电极周围的微环境。葡萄糖氧化酶被用于该研究中，并且传感器的稳态响应与高达5 mM的葡萄糖浓度成比例。 ...更多信息 葡萄糖浓度为0.01 mM，以二茂铁甲醛为电子媒介，克服了溶解氧浓度降低引起的灵敏度下降.石英晶体微天平生物传感器研究了压电晶体在不同操作条件下的变化，并将其应用于人IgG浓度的测定。用酪胺和戊二醛将羊抗人IgG固定在晶体电极表面，对AT切割晶体进行修饰，使晶体的基频为9 MHz。固定化技术提高了生物传感器的长期稳定性，并且证实了由材料吸附到电极表面上引起的频率变化为1Hz/ng。人IgG和山羊抗人IgG反应产生的频率偏移与10μg/ml-50 μg/ml的浓度范围相关。这种技术的神经生理学研究的适用性，证实了在体内的化学波动的调查。少

The purpose of this research project was to accomplish the biosensing system which can detect the endogenous chemical substances influencing neuronal activities in the brain. For this purpose, the characteristics of the following sensors were studied ; (1) enzyme microdialysis biosensor and (2) a quarts crystal microbalance biosensor for immunosorbent assay.1. Enzyme microdialysis biosensorThe concentric biosensor was consisted of glass body with a semi-permeable membrane at the tip, working electrode and an inlet and outlet capillary for the perfusion of enzyme solution. The working electrode and the inlet capillary were inserted into a semi-permeable hollow fiber (o.d.=220 μm). The advantage of the biosensor was that the micro-environment around the working electrode could be easily changed by perfusing the enzyme solution. Glucose oxidase was used in this study and steady state response of the sensor was proportional to the glucose concentration up to 5mM.The detection limit of the … More glucose concentration was 0.01 mM.The decrease in the sensitivity caused by the reduction of dissolved oxygen concentration was overcome by using ferrocene carboxyaldehyde as an electron mediator.2. Quarts crystal microbalance biosensorThe piezoelectric crystals were studied under various operational conditions and were also applied to the determination of human IgG concentration. AT-cut crystals, with a basic resonant frequency of 9 MHz, were modified by immobilizing goat anti-human IgG onto the surface of crystal electrode with tyramine and glutaraldehyde. The immobilization technique improved the long term stability of the biosensor, and the change in frequency caused by the adsorption of material onto the surface of electrode was confirmed to be 1 Hz/ng. The shift in frequency resulting from the reaction of human IgG and goat anti-human IgG correlated with a concentration range of 10μg/ml-50 μg/ml. The suitability of this technique for neurophysiological studies was confirmed for investigation of the chemical fluctuations in vivo. Less