Abstract
A light-addressable potentiometric sensor (LAPS) with Poly-L-Omithine with Laminin (PLOL)-coated SiO2 layer as the only insulating material on the bulk Si in SiO2/Si structure, is investigated as a possible biological interface. Comparing with the conventional structure (Si3N4/SiO2/Si) of the LAPS, much steeper photocurrent response was observed for the PLOL-coated SiO2/Si structure, which shows higher surface potential sensitivity and pH resolution. PLOL-coated SiO2 layer is kept soaked with the electrolyte for ten days and no appreciable change in the surface potential sensitivity was noticed. The pH sensitivity of the sensor was investigated in the pH range of pH4 to pH10, and a nearly Nernstian sensitivity was observed.
