The ability to control surface-analyte interaction allows tailoring chemical sensor sensitivity to specific target molecules. By adjusting the bias of the shallow p-n junctions in the electrostatically formed nanowire (EFN) chemical sensor, a multiple gate transistor with an exposed top dielectric layer allows tuning of the fringing electric field strength (from 0.5 × 10 to 2.5 × 10 V/m) above the EFN surface. Herein, we report that the magnitude and distribution of this fringing electric field correlate with the intrinsic sensor response to volatile organic compounds. The local variations of the surface electric field influence the analyte-surface interaction affecting the work function of the sensor surface, assessed by Kelvin probe force microscopy on the nanometer scale. We show that the sensitivity to fixed vapor analyte concentrations can be nullified and even reversed by varying the fringing field strength, and demonstrate selectivity between ethanol and n-butylamine at room temperature using a single transistor without any extrinsic chemical modification of the exposed SiO surface. The results imply an electric-field-controlled analyte reaction with a dielectric surface extremely compelling for sensitivity and selectivity enhancement in chemical sensors.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acssensors.7b00754 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Three-Dimensional Surface Reconstruction for Specular/Diffuse Composite Surfaces.
Sensors (Basel)
December 2024
Department of Electrical Engineering, Chinese Culture University, Taipei 11114, Taiwan.
This paper presents an effective three-dimensional (3D) surface reconstruction technique aimed at profiling composite surfaces with both specular and diffuse reflectance. Three-dimensional measurements based on fringe projection techniques perform well on diffuse reflective surfaces; however, when the measurement targets contain both specular and diffuse components, the efficiency of fringe projection decreases. To address this issue, the proposed technique integrates digital holography into the fringe projection setup, enabling the simultaneous capture of both specular and diffuse reflected light in the same optical path for full-field surface profilometry.
View Article and Find Full Text PDFMicrobial fuel cells to monitor natural attenuation around groundwater plumes.
Environ Sci Pollut Res Int
January 2025
School of Natural and Built Environment, Queen's University Belfast, Belfast, Northern Ireland, BT7 1NN, UK.
This research presents a straightforward and economically efficient design for a microbial fuel cell (MFC) that can be conveniently integrated into a borehole to monitor natural attenuation in groundwater. The design employs conventional, transparent, and reusable PVC bailers with graphite tape and granular activated carbon to create high surface area electrodes. These electrodes are connected across redox environments in nested boreholes through a wire and variable resistor setup.
View Article and Find Full Text PDFFast Multifrequency Phase Unwrapping Method Based on 3D Printing Object Appearance Acquisition.
3D Print Addit Manuf
October 2024
School of Electrical Engineering, Yancheng Institute of Technology, Yancheng, Jiangsu, China.
3D printing is an indispensable technology in modern life and is widely used in aerospace, exoskeleton, and architecture. The increasing accuracy requirements of 3D printed objects in these fields require high-precision measurement methods to obtain accurate data. Based on the precision measurement requirements, in this study, a fast multifrequency phase unwrapping method based on 3D printing object appearance acquisition is proposed.
View Article and Find Full Text PDFIn situ characterization of the electric field of ultrafast pulses is critical in multiphoton microscopy. Although second harmonic generation-based collinear Frequency-Resolved Optical Gating (FROG) addresses this need, the interferometric measurement is challenged by interferometric drift instability, the required high sampling density of the acquired data, and the inability to directly use the interferometric data with conventional FROG retrieval algorithms. We address these issues by combining low-pass Fourier filtering with active kHz dithering of the interferometric path length difference using a piezo-driven retroreflector.
View Article and Find Full Text PDFDirect magnetic imaging of fractional Chern insulators in twisted MoTe.
Nature
November 2024
Department of Physics, University of California Santa Barbara, Santa Barbara, CA, USA.
Orbital magnetization provides a sensitive probe of topology and interactions, with particularly rich phenomenology in Chern insulators in which the topological edge states carry large equilibrium currents. Here we use a nanoscale superconducting sensor to map the magnetic fringe fields in twisted bilayers of MoTe, in which transport and optical sensing experiments have revealed the formation of fractional Chern insulator (FCI) states at zero magnetic field. We observe oscillations in the local magnetic field associated with fillings ν = -1, -2/3, -3/5, -4/7 and -5/9 of the first moiré hole band, consistent with the formation of FCIs at these fillings.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!