This paper presents photosensitive biosensor array chips with the simple photodiode array having the optical input signal and the electrical output signal, which detects the photocurrent change caused by a reaction between probe molecules and target molecules. Using the properties having the optical input, the addressing circuit on the array chips was removed for the low cost application and the real cell addressing was achieved by the LED array module outside of the chips. PSA antigen capturing in the serum was performed by the sandwich-type immunogold assay which was using the anti-PSA conjugated Au nanoparticles. To enhance the sensitivity of the photosensitive biosensor from growing the nanoparticles immobilized on the surface, Ag staining process was adapted, resulting in covering most of the area with Ag from just 9 min dipping in case of 10 ng/ml PSA. The 5X5 LED array module, which is PC-controllable, was designed and assembled for emitting the light on the individual cell. The photocurrent on the biosensor tested on the LED array module shows the monotonic decrease with increasing the PSA concentration, indicating roughly 1 ng/ml resolution in the PSA detection. The multi-detection results on the photosensitive biosensor array chips will be also presented.
Journal: TechConnect Briefs
Volume: 3, Nanotechnology 2010: Bio Sensors, Instruments, Medical, Environment and Energy
Published: June 21, 2010
Pages: 31 - 34
Industry sectors: Medical & Biotech | Sensors, MEMS, Electronics
Topics: Chemical, Physical & Bio-Sensors, Diagnostics & Bioimaging