Abstract
This study demonstrated that the pH-sensors and biosensors based on boron-doped silicon nanowire field effect transistors (SiNW-FETs) are highly sensitive and selective for detections. N-(2-aminoethyl)-3-aminopropyltri-methoxysilane (AEAPTMS) functionalized SiNWs were adopted to detect the change of surface states in different pH level solutions. Furthermore, the change in conductance will be monitored, when the binding event of anti-rabbit IgG and steroid occurs on the rabbit IgG and ketosteroid isomerase modified surface, respectively. In order to reduce the consumption of the sample volume, we delivered the molecule and buffer solutions through the SiNW by means of the microfluidic channel. Two types of microfluidic channel (SU8, PDMS) were adopted through this study. The study also found that the conductance of amino-functionalized SiNW-FET nanosensors was linearly changed with the change of pH value. The sensitivity of SiNW-FET pH-sensor is about 95 nS/pH for the pH values from 5 to 9. Detection of the anti-rabbit IgG in a concentration of 10-12 g/ml was also achieved. Also, steroid detection was demonstrated on the silicon microwire sensors.