Solution pH Effect on Drain-Gate Characteristics of SOI FET Biosensor

Nanowire or nanobelt sensors based on silicon-on-insulator field-effect transistors (SOI-FETs) are one of the leading directions label-free biosensors. An essential issue in this device construction type is obtaining reproducible results from electrochemical measurements. It affected by many factors, including measuring solution and design parameters sensor. The biosensor surface should be charged minimally for highest sensitivity maximum effect interaction with other molecules. Therefore, pH value chosen so that has a minimum charge. Here, we studied SOI-FET sensor containing 12 elements concatenated single substrate. Two types sensing similar different widths (0.2 3 ?m) were located chips. drain-gate measurements wires width µm sufficiently entire chip to obtain measurement statistics air deionized water. For values 12, found significant changes source-drain characteristics nanobelts, which reach plateau at 7 higher. High (ca. 1500 970 mV/pH) was observed ?m 0.2 range 7. We higher “on” current “off” ratio wide wires. At all values, Ion/Ioff up 4600 30,800 wires, respectively. In scheme fixed gate voltages, reaches voltage 13 19 V sensors, summary, most suitable reliable analysis biomolecules over