A pH sensor with a double-gate silicon nanowire field-effect transistor

Abstract

A pH sensor composed of a double-gate silicon nanowire field-effect transistor (DG Si-NW FET) is demonstrated. The proposed DG Si-NW FET allows the independent addressing of the gate voltage and hence improves the sensing capability through an application of asymmetric gate voltage between the two gates. One gate is a driving gate which controls the current flow, and the other is a supporting gate which amplifies the shift of the threshold voltage, which is a sensing metric, and which arises from changes in the pH. The pH signal is also amplified through modulation of the gate oxide thickness. V

FinFET integrated low-power circuits for enhanced sensing applications

“…The FinFET-based sensing amplifier can then achieve a readout sensitivity that is at least ten times higher than that of individually addressable single sensors, for which the sensitivity is limited by the Nernst equation to 59 mV/pH. The signal boost results from the specific circuit design, whereas in previous work the sensitivity limit has been overcome by using a back gate [10,11] or double side gates [25,26]. The previously described approach (back or side gates) neither can be optimized in terms of design parameters, such as load and driver transistor lengths, nor is the effect of the supply voltage taken into account in view of possible integration of the devices.…”

“…The previously described approach (back or side gates) neither can be optimized in terms of design parameters, such as load and driver transistor lengths, nor is the effect of the supply voltage taken into account in view of possible integration of the devices. The use of metal double-gates can also drastically limit the sensor surface area that is exposed to the analyte [25,26].…”

Drain Current Model of a Four-Gate Dielectric Modulated MOSFET for Application as a Biosensor

“…Therefore, this situation has also been modeled in this paper. The architecture presented in this paper can be built using the methods/techniques mentioned in the following references for double-gate biosensor [18], [19]. The present work is an extension of our previously reported work in ICDCS'14 conference proceeding [20].…”

Development of a pH sensing membrane electrode based on a new calix[4]arene derivative

“…Although pH-sensitive glass electrode has distinguished response characteristics and has been in use for such a long period, it has certain setbacks such as its high resistance, fragility, its instability in hydrofluoric acid or fluoride solutions, alkaline and acid errors and its unsuitability to serve as a microelectrode for biological applications [4,5]. Accordingly, the studies to develop non-glass pH-sensitive electrodes such as solid contact electrodes (SCE's) [1,[6][7][8][9][10][11][12][13], coated wire electrodes (CWE's) [13,14], field effect transistors (FET's) [15,16], nanorod based electrodes [17,18] and polymeric membrane electrodes [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] have gained interest. Among these, PVC membrane electrodes are the preferred ones due to their low electrical resistance and ease of construction [31,32].…”