Silicon dioxide ion-sensitive field effect transistors were modified by silylation with methacryloxypropyltrimethoxysilane (MPTS) and with in situ photopolymerized poly(hydroxyethyl methacrylate). Subsequently, the covalently linked methacrylate was swollen with a buffered potassium chloride solution, prior to the introduction of a hydrophobic sensing membrane. The introduced hydrogel layer effects a significant reduction in the peak-to-peak noise levels and eliminates completely interference from carbon dioxide. The method is compatible with integrated circuit photolithographic techniques and improves the development of potentiometric biosensors and chemical sensors.
Sudhölter, E. J. R., van der Wal, P. D., Skowronska-Ptasinska, M., van den Berg, A., Bergveld, P., & Reinhoudt, D. N. (1990). Modification of ISFESTs by covalent anchoring of poly(hydroxyethyl methacrylate) hydrogel. Introduction of a thermodynamically defined semiconductor-sensing membrane interface. Analytica chimica acta, 230(3), 59-65. https://doi.org/10.1016/S0003-2670(00)82761-0