Room temperature selective sensing of aligned Ni nanowires using impedance spectroscopy

Mohammadi, Mohammad; Fardindoost, Somayeh; zad, Azam Iraji; Almasi-Kashi, Mohammad

doi:10.1088/2053-1591/ab66ac

Cited by 8 publications

(6 citation statements)

References 38 publications

(41 reference statements)

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“…In general, impedance measured in capacitive systems strongly depends upon charge transfer processes occurring at the electrode-vapor interface. As such, impedance spectroscopy exhibits pronounced sensitivity to electrode surface properties and illuminates surface properties and processes occurring through adsorption of gas molecules [ 45 ]. Figure 3 a depicts the Nyquist plots recorded for the orange C-dot-IDE in different humidity conditions (i.e., different RH values).…”

Section: Resultsmentioning

confidence: 99%

Sniffing Bacteria with a Carbon-Dot Artificial Nose

et al. 2021

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Highlights Novel artificial nose based upon electrode-deposited carbon dots (C-dots). Significant selectivity and sensitivity determined by “polarity matching” between the C-dots and gas molecules. The C-dot artificial nose facilitates, for the first time, real-time, continuous monitoring of bacterial proliferation and discrimination among bacterial species, both between Gram-positive and Gram-negative bacteria and between specific strains. Machine learning algorithm furnishes excellent predictability both in the case of individual gases and for complex gas mixtures. Abstract Continuous, real-time monitoring and identification of bacteria through detection of microbially emitted volatile molecules are highly sought albeit elusive goals. We introduce an artificial nose for sensing and distinguishing vapor molecules, based upon recording the capacitance of interdigitated electrodes (IDEs) coated with carbon dots (C-dots) exhibiting different polarities. Exposure of the C-dot-IDEs to volatile molecules induced rapid capacitance changes that were intimately dependent upon the polarities of both gas molecules and the electrode-deposited C-dots. We deciphered the mechanism of capacitance transformations, specifically substitution of electrode-adsorbed water by gas molecules, with concomitant changes in capacitance related to both the polarity and dielectric constants of the vapor molecules tested. The C-dot-IDE gas sensor exhibited excellent selectivity, aided by application of machine learning algorithms. The capacitive C-dot-IDE sensor was employed to continuously monitor microbial proliferation, discriminating among bacteria through detection of distinctive “volatile compound fingerprint” for each bacterial species. The C-dot-IDE platform is robust, reusable, readily assembled from inexpensive building blocks and constitutes a versatile and powerful vehicle for gas sensing in general, bacterial monitoring in particular.

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Section: Resultsmentioning

confidence: 99%

Sniffing Bacteria with a Carbon-Dot Artificial Nose

et al. 2021

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“…Classical works on the EIS-based sensorics are focused on analysis of the change in spectra upon an analyte exposure 15,51 and analysis of real or imaginary parts of sensor impedance. 52 The reported approaches do not allow for the selective detection of two or more target substances and their mixtures 51,53 limiting their applicability. Here, we fabricate Si NW-based sensors and thoroughly examine their electronic properties with an aid of EIS upon exposure to NH 3 and HCl vapors and their mixtures.…”

Section: Introductionmentioning

confidence: 99%

Si Nanowire-Based Schottky Sensors for Selective Sensing of NH₃ and HCl via Impedance Spectroscopy

Kondrat'ev

Vyacheslavova

Shugabaev³

et al. 2023

ACS Appl. Nano Mater.

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This work is aimed at the development of a highly sensitive silicon (Si)-based sensor allowing for the selective detection and analysis of liquid solution compositions containing ammonia (NH3) and hydrochloric acid (HCl) in an indirect manner using electrochemical impedance spectroscopy (EIS). For optimization of the performance, we develop three types of sensors based on as-fabricated Si nanowires, nanowires treated with hydrofluoric acid (HF), and nanowires decorated with silver (Ag) nanoparticles. The fabricated sensors exhibit good performance governed by the sensitivity of the nanoscale Schottky barriers at the interface between the golden pads and Si nanowires. The best results on sensitivity are obtained with untreated Si nanowires providing a detection limit at the level of 4 μmol·L–1 and resistive sensitivities of 0.8% per μmol·L–1 for HCl and 4 μmol·L–1, −0.2% per μmol·L–1 for NH3, correspondingly. Treatment with HF stimulates the surface oxidation providing higher density of the adsorption sites and found promising for the detection with the analyte content up to 1000 μmol·L–1. In the end, we study the sensor response upon simultaneous exposure under NH3 and HCl vapors using developed approach for the EIS data analysis involving characterization of the sensor response with two parametersresistance and EIS frequency corresponding to the change in the operation regime. Due to the use of two parameters simultaneously, this approach is found as a pathway for qualitative analysis of the gas mixture composition using only one sensor. The results of the work shed light on the development of feasible highly sensitive sensors for health monitoring, allowing for selective mixed analytes detection.

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“…So, we expect that the one-dimensional (1D) nanowires can provide a much higher surface area, as compared to thin film or bulk materials. As reported for the 1D nanowire arrays, the number of surface active sites for the absorption of water molecules increases, resulting in the overall change of the sensing conduction and increase of the humiditysensitive characteristic of the sensor [22][23][24][25].…”

Section: Introductionmentioning

confidence: 59%

Aligned Grid Shaped NiO Nanowires for Humidity Sensing at Room Temperature

Mohammadi

Almasi-Kashi

Fardindoost

et al. 2020

Preprint

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A grid configuration based on the aligned nickel oxide nanowire (NiO NW) for humidity sensing were fabricated through the oxidation of ferromagnetic nickel NWs prepared by a template-assisted electrodeposition process. Their structure and elemental compositions were characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and energy-dispersive X-ray analyses (EDAX). The room-temperature humidity sensing behavior of the NiO NWs was investigated successfully based on DC and AC impedance spectroscopy (IS) method in frequencies range 10 Hz to 2 MHz. The sensors showed excellent humidity sensing characteristics such as a high response of about 66 with rather rapid response-recovery times about 9 and 2 s for 90%RH, and good stability. The equivalent circuits were simulated for impedance responses to humidity in the range of 40–90% RH. According to the results, ionic conduction via NW-NW junctions as well as NW-electrode interfaces in the grid configuration is responsible for sensing behavior.

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Room temperature selective sensing of aligned Ni nanowires using impedance spectroscopy

Cited by 8 publications

References 38 publications

Sniffing Bacteria with a Carbon-Dot Artificial Nose

Sniffing Bacteria with a Carbon-Dot Artificial Nose

Si Nanowire-Based Schottky Sensors for Selective Sensing of NH₃ and HCl via Impedance Spectroscopy

Aligned Grid Shaped NiO Nanowires for Humidity Sensing at Room Temperature

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Room temperature selective sensing of aligned Ni nanowires using impedance spectroscopy

Cited by 8 publications

References 38 publications

Sniffing Bacteria with a Carbon-Dot Artificial Nose

Sniffing Bacteria with a Carbon-Dot Artificial Nose

Si Nanowire-Based Schottky Sensors for Selective Sensing of NH3 and HCl via Impedance Spectroscopy

Aligned Grid Shaped NiO Nanowires for Humidity Sensing at Room Temperature

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Product

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Si Nanowire-Based Schottky Sensors for Selective Sensing of NH₃ and HCl via Impedance Spectroscopy