细菌视紫红质的光电响应特性和机制

在ITO导电玻璃上制备定向细菌视紫红质 (BR)电泳沉积膜或LB膜组成光电池系统 ,在短脉冲激光照射下 ,测定其脉冲响应光电压 ;在间断光照射下 ,测定其对光强变化产生的微分响应信号。对脉冲光电响应和微分响应的机理及其关系进行理论分析和解释 ,认为脉冲响应是BR分子内部生色团快速光极化引起的电荷分离和希夫碱及其周围氨基酸去质子化和再质子化过程引起的质子定向运输产生的位移电流 ,是一个快反应过程 ,是微分响应的早期反应和基础。微分响应则是由于菌紫质的光驱动质子泵产生的连续质子流在光开和光关瞬间引起光电池系统充放电以及测量电路的耦合特性引起的 ,是一个慢变化过程

Characteristics and the Mechanism of Bacteriorhodopsin Photoelectric Response

Oriented bacteriorhodopsin films were prepared on ITO conductive glass by using electrophoretic or Langmuir Blodgett methods to construct photocells. Pulse response photovoltages under stimulation of pulsed laser and differential response signals under irradiation of discontinued light were respectively measured, and the origins of the two responses and their correlation are analyzed. The pulse response photovoltage initiated from the ultrafast charge separation of the retinal and the proton translocation, followed by the deprotonation and reprotonation of the Schiff base and its surrounding amino acids. This was a quick response and was the preceding reaction of the differential response. The differential response was caused by the charging and discharging of the continuous proton current of the BR light driven proton pump at the light on and light off, as well as the coupling mode of the measuring circuit, which was a slow process.