Impedance-Based Miniaturized Biosensor for Ultrasensitive and Fast Prostate-Specific Antigen Detection
Figure 1
(A) Biosensor fabrication process flow: (a) RCA clean Si wafer, (b) thermal oxidation to grow 500 nm SiO2 as an insulation layer, (c) apply photoresist, (d) expose and pattern photoresist, (d) deposit Au using electron beam (e-beam) evaporator with a thickness of 200 nm and lift-off photoresist to get patterned Au electrodes, (f) apply photoresist, (g) pattern photoresist, and (h) finally deposit Ag using e-beam evaporator with thickness of 200 nm and lift-off is used to remove photoresist and excess metal on top of it. (B) Biosensor actual view under a microscope (10x): (1) gold working interdigitated electrodes; (2) silver pseudoreference electrode; (3) gold counter electrode; and (4) SU8 reagent chamber.
