Characteristics of the Multifunctional Biosensors for the Measurements of Bioactive Substances in the Living Body

本研究的目的是研制一种能够检测脑内影响神经元活动的内源性物质的生物传感器。为此，研究了以下传感器的特性：(1)用于生物活性物质分离和分析的微渗析传感器，(2)用于检测葡萄糖氧化酶的酶生物传感器，(3)用于免疫吸附分析的石英晶体微天平传感器。本文研究了微透析生物传感器去甲肾上腺素在大鼠内侧前额叶皮质和脾中的释放。在信噪比为3：1时，微渗析传感器系统对去甲肾上腺素的检出限为500fg/40mul。一系列的药理和生理操作实验表明，透析液中回收的去甲肾上腺素主要来源于神经末梢。酶生物传感器将葡萄糖氧化酶固定在铂电极上，获得稳定的酶活性。《浓缩液》(The Content…)对葡萄糖浓度在0.1-10.0 mM范围内传感器的响应特性和稳定性进行了研究。传感器的稳态响应与葡萄糖浓度成正比，最大为5 mM。传感器响应的线性相关斜率与溶解氧浓度成反比。以二茂铁缩甲醛为电子媒介，克服了由于溶解氧浓度降低而导致的传感器响应降低的问题。采用由AT-Cut石英晶体、振荡器和频率计数器组成的压电晶体生物传感器系统测定人免疫球蛋白G(Ig G)。用酪胺和戊二醛将抗人免疫球蛋白固定在金电极表面。在10-50µg/ml的范围内，抗体与抗体亲和反应产生的共振频移与抗体浓度呈正相关，晶体传感器对牛血清白蛋白无响应。较少

The purpose of this research project was to accomplish the biosensors which can detect the endogenous substances influencing neuronal activity in the brain. For this purpose, the characteristics of the following sensors were studied ; (1) microdialysis sensor for separation and analysis of bioactive substances, (2) enzyme biosensor for detection of glucose immobilized with glucose oxidase and (3) a quartz crystal microbalance sensor for immunosorbent assay.1. Microdialysis biosensorNoradrenaline release in the medial prefrontal cortex and spleen of rats was studied. The detection limit of the microdialysis sensor system for noradrenaline was 500 fg/40 mul at a 3 : 1 signal to noise ratio. A series of experiments using pharmacological and physiological manipulations indicated that the noradrenaline recovered in the dialysate was mainly derived from nerve terminals.2. Enzyme biosensorGlucose oxidase was immobilized onto platinum electrode to attain stabilized activity. The concentration … More response characteristics and the stability of the sensor were studied for glucose concentrations of 0.1-10.0mM.Steady state response of the sensor was proportional to the glucose concentration up to 5 mM.The slope of the linear correlation of sensor response was inversely proportional to the dissolved oxygen concentration. The decrease in sensor response caused by the reduction of dissolved oxygen concentration was overcome by using ferrocene carboxialdehyde as an electron mediator.3. Quartz crystal microbalance sensorDetermination of human immunoglobulin G (IgG) was performed by using a piezoelectric crystal biosensor system, which was consist of an AT-cut quarts piezoelectriccrystal, oscillator and frequency counter. Anti-human IgG was immobilized onto the surface of the gold electrode with tyramine and glutaraldehyde. The resonant frequency shift resulting from the affinity reaction of anti-IgG and IgG correlated with a concentration of IgG in the range of 10mug/ml-50mug/ml. The crystal sensor showed no response to bovine serum albumin. Less