Preliminary test of the scanning system for the differential photocurrents of a purple-membrane coated chip

• Main Authors: Yu-An Chen, 諶宥銨
• Other Authors: Hsiu-Mei Chen
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/8yf5tt

碩士 === 國立臺灣科技大學 === 化學工程系 === 106 === The purple membrane (PM) of Halobacterium salinarum contains bacteriorhodopsin (BR), which generates photocurrents upon illumination. This research aimed to analyze the differential photocurrents of PM chips obtained using an automatic scanning system we had previously set up, as well as to study the potential applications of this system. Four topics were investigated. First, by tuning the optical intensity of the illuminating laser with lens of different focal lengths, a power relationship between the differential photocurrent densities and the incident optical intensities was obtained. Second, scanning the coating regions of PM chips led to a finding that the chips prepared with oxidized avidin complexed with graphene oxide of different sizes as the linker had more uniform photocurrent-density distributions than the ones prepared with only pure oxidized avidin. Post-deposition washing the PM chips with a microfluidic flow further improved the uniformity of the distributions, suggesting that GO addition reduced PM stacking, which resulted in locally high photocurrents. Third, blurry images of several different designed graphics were converted from the scanned photocurrent-density profiles of PM chips whose incident light had first passed through a transparency black-printed with each designed graphic, which mimicked retinal imaging. Finally, a slight increase was nevertheless observed in the average of the scanned photocurrent densities of a PM chip whose incident light had first passed through a glass slide covered with grown dental-plaque biofilm. The increase was attributed to the diffusion of the illuminated spot caused by light scattering from the three-dimensional biofilm.