Study on the Carbon Nanotube Separative Structure for the Extended Gate H^+-Ion Sensitive Field Effect Transistor

We use the carbon nanotube (CNT) as the material of the pH sensing layer of the separative structure for the extended gate H^+-ion sensitive field effect transistor (EGFET) device.The CNT paste was prepared with CNT powder,Ag powder,silicagel,the di-n-butyl phthalate and the toluene solvents by appropriate ratio,then immobilized on the silicon substrate to form the carbon nanotube sensing layer.We measured theⅠ_(DS)-Ⅴ_G curves of the carbon nanotube separative structure EGFET device in the different pH buffer solutions by the Keithley 236Ⅰ-Ⅴmeasurement system.According to the experimental results,we can obtain the pH sensitivities of the carbon nanotube separative structure EGFET device,which is 62.54mV/pH from pH1 to pH13.

We use the carbon nanotube （CNT） as the material of the pH sensing layer of the separative structure for the extended gate H^＋-ion sensitive field effect transistor （EGFET） device. The CNT paste was prepared with CNT powder, Ag powder, silicagel, the di-n-butyl phthalate and the toluene solvents by appropriate ratio, then immobilized on the silicon substrate to form the carbon nanotube sensing layer. We measured the IDs-Vc curves of the carbon nanotube separative structure EGFET device in the different pH buffer solutions by the Keithley 236 I-V measurement system. According to the experimental results, we can obtain the pH sensitivities of the carbon nanotube separative structure EGFET device, which is 62.54mV/pH from pHI to pH13.