| Autor: |
Le ST; Nanoscale Device Characterization Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA and Theiss Research, La Jolla, CA 92037, USA., Guros NB; Microsystems and Nanotechnology Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA. arvind.balijepalli@nist.gov and Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD 20742, USA., Bruce RC; Nanoscale Device Characterization Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA., Cardone A; Software and Systems Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA and University of Maryland Institute for Advanced Computer Studies, University of Maryland, College Park, MD 20742, USA., Amin ND; National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA., Zhang S; Nanoscale Device Characterization Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA and Theiss Research, La Jolla, CA 92037, USA., Klauda JB; Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD 20742, USA., Pant HC; National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA., Richter CA; Nanoscale Device Characterization Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA., Balijepalli A; Microsystems and Nanotechnology Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA. arvind.balijepalli@nist.gov. |
| Abstrakt: |
We have demonstrated atomically thin, quantum capacitance-limited, field-effect transistors (FETs) that enable the detection of pH changes with 75-fold higher sensitivity (≈4.4 V per pH) over the Nernst value of 59 mV per pH at room temperature when used as a biosensor. The transistors, which are fabricated from monolayer films of MoS 2 , use a room temperature ionic liquid (RTIL) in place of a conventional oxide gate dielectric and exhibit very low intrinsic noise resulting in a pH resolution of 92 × 10 -6 at 10 Hz. This high device performance, which is a function of the structure of our device, is achieved by remotely connecting the gate to a pH sensing element allowing the FETs to be reused. Because pH measurements are fundamentally important in biotechnology, the increased resolution demonstrated here will benefit numerous applications ranging from pharmaceutical manufacturing to clinical diagnostics. As an example, we experimentally quantified the function of the kinase Cdk5, an enzyme implicated in Alzheimer's disease, at concentrations that are 5-fold lower than physiological values, and with sufficient time-resolution to allow the estimation of both steady-state and kinetic parameters in a single experiment. The high sensitivity, increased resolution, and fast turnaround time of the measurements will allow the development of early diagnostic tools and novel therapeutics to detect and treat neurological conditions years before currently possible. |
