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The present work deals with fabrication and characterization of the zinc oxide (ZnO) nanowire based novel two‐electrode capacitive biosensors on flexible Polyethylene terephthalate (PET) substrates for accurate estimation of glucose by analyzing the fundamental dielectric nature of the relevant sample. The morphology and crystalline quality of grown nanowires are analyzed by using field‐emission scanning electron microscope (FESEM) and X‐ray diffractometer (XRD), respectively. Current and capacitance values of the device have been studied for ten different glucose concentrations relevant to the physiological standards. The analytical performance of the devices in terms of enzyme activity, reliability and flexibility has also been evaluated. [ABSTRACT FROM AUTHOR]

In this work, the performance of a Double-Gated Silicon on Insulator (DG-SOI) Dielectrically Modulated Tunnel Field Effect Transistor (DMTFET) architecture is systematically investigated for label-free bio-sensing applications with the help of extensive device-level simulations. In this context, the effects of bulk oxide (BOX) substrate and back-gate biasing are emphasized and analyzed from the cavity and channel electrostatics and Band to Band Tunneling (BTBT) component of DMTFET. It is found that the electrostatic coupling between BOX substrate and channel significantly degrades the sensing performance of DG-SOI DMTFETs, whereas an applied negative back-gate bias enhances the performance of such transducer. In this line, a dual metal (DM) gate architecture is introduced that can effectively enhance the influence of applied back-gate bias and thereby leads to sensitivity improvement from 10% to 110% in DM DG-SOI DMTFET depending on bio-molecule sample specifications. Furthermore, it is observed that for suitable applied back-gate bias, the interface trap-state induced variations in sensitivity of DG-SOI DMTFETs can be reduced by even an order of magnitude. Finally, a comparative sensing performance study of proposed DMTFET with their reported counterparts establishes the advantage of such biosensors for bio-molecules with smaller dielectric constant. A similar study also shows the superiority of the proposed DMTFET over its MOSFET counterpart for wide bio-molecular sample specifications. [ABSTRACT FROM AUTHOR]

In this work, an inverter-based biomolecule detection strategy has been introduced for dielectrically modulated biosensing applications that show a clear output logic-state transition after conjugation. Subsequently, a bioring-oscillator has been realized based on such bioinverters, where biomolecules can be detected from the oscillation frequency amplification with conjugation. To optimize the detection efficiency, a dielectrically modulated fringing field effect transistor based transducer has been incorporated as the pull-up/pull-down elements of such bioinverter. The underlying physics of such structure has been investigated and subsequent electrical response has been estimated for various biomolecule sample specifications. This work explores different bioinverter configurations, and subsequently the suitable choice of bioinverter has been indicated for charged and charge-neutral biomolecule detection. Similar studies have been performed for bioring oscillator, and the roles of supply voltage scaling and oscillator stage enhancement have been investigated in this context. [ABSTRACT FROM PUBLISHER]

In this paper, a dielectrically modulated fringing field-effect-transistor (DMFFET) structure has been introduced as the transducer element for electrochemical biosensing applications, where the gate-induced fringing field has been exploited for transduction. This detection principle is different from that of the direct gate field modulation in conventional dielectrically modulated field-effect-transistor (DMFET)-based transducers. This paper explores the transduction mechanism from the electrostatics and carrier transport mechanism of DMFFET, in comparison with conventional double gated (DG) DMFET, based on extensive device-level simulation. The transducer response for the DMFFET/DG-DMFET structures has been estimated in terms of the drain current sensitivity, which is defined in the dB scale. In this paper, the effects of gate/drain biases have been investigated in details, and a strategy has been proposed for identifying suitable biasing ranges of operation based on half width at full maxima limit of sensitivity. The relative influences of electron trapping/de-trapping at the interfaces are also indicated on the transducer responses. Further, the role of different gate-related structural parameters of DMFFET has been considered for sensitivity-optimization. The comparative performance study with the reported DMFETs indicates the inherent superiority of DMFFET for transduction. [ABSTRACT FROM PUBLISHER]

Dielectrically modulated tunnel FET (DMTFET)-based biosensors show higher sensitivity but lower subthreshold current compared with their dielectrically modulated FET counterpart. In this context, the effect of use of silicon–germanium (SiGe) source and n+-pocket-doped channel is investigated with the help of extensive device-level simulations. This paper explores the underlying physics of germanium composition variation in the source region, and doping concentration variation in n+-pocket region, from the perspective of biomolecule conjugation. The effects of source bandgap and tunneling length over the band-to-band tunneling component have been analyzed, and, subsequently, the sensing performance of DMTFETs has been estimated. The results show that SiGe-source DMTFET has significant superiority over n+-pocket DMTFET for attaining higher subthreshold current level while retaining acceptable sensitivity. Such sensitivity-current optimization has been studied for different gate and drain biases, and the suitable biasing range of operation has been indicated. In addition, the relative efficiency of SiGe source and n+-pocket-doped channel has been studied under different biomolecule sample specifications. Finally, the influence of trap-assisted tunneling on DMTFET sensing performance has been analyzed, and the comparative role of SiGe source and n+ pocket has also been indicated in this context. [ABSTRACT FROM AUTHOR]

In this paper, a short-gate tunneling-field-effect-transistor (SG-TFET) structure has been investigated for the dielectrically modulated biosensing applications in comparison with a full-gate tunneling-field-effect-transistor structure of similar dimensions. This paper explores the underlying physics of these architectures and estimates their comparative sensing performance. The sensing performance has been evaluated for both the charged and charge-neutral biomolecules using extensive device-level simulation, and the effects of the biomolecule dielectric constant and charge density are also studied. In SG-TFET architecture, the reduction of the gate length enhances its drain control over the band-to-band tunneling process and this has been exploited for the detection, resulting to superior drain current sensitivity for biomolecule conjugation. The gate and drain biasing conditions show dominant impact on the sensitivity enhancement in the short-gate biosensors. Therefore, the gate and drain bias are identified as the effective design parameters for the efficiency optimization. [ABSTRACT FROM AUTHOR]