pH sensor using protein-mediated gold nanocrystal array

pH sensitivity of protein mediated gold nanocrystals modified SiO₂ have been investigated using a capacitive EIS (electrolyte-insulator-semiconductor) structure and compared with bare SiO₂. The SiO₂ surface was first silanized using phenyltriethoxy and then a chaperonin protein array was formed on SiO₂ surface. Finally, the chaperonin protein lattice is used to deposit gold nanocrystal on SiO₂ surface in the EIS structure. The electrochemical characterization of EIS sensors was done by means of C-V measurement in pH buffer solutions of values from 2 to 12. The average sensitivity of gold modified SiO₂ senor was 33 mV/pH and SiO₂ senor was 35 mV/pH while the linearity was 99.37% and 98.35%, respectively.