Room-temperature Detectors Research Articles

The synergy of Pd nanoparticles and oxygen vacancy to modulate SnO2 modified reduced graphene oxide hybrids for room-temperature ppb-level NO2 detection

Reduced graphene oxides (RGO)-based materials exhibit high carrier mobility and selective recognition ability to NO2, making them constitute promising platform for room-temperature NO2 detection. However, the low sensitivity becomes the main bottleneck for their further development. Here, we demonstrate that synergy of Pd nanoparticles (NPs) and oxygen vacancies can modulate the surface active sites over SnO2 NPs modified RGO hybrids (labeled as SR), leading to improving the sensitivity of room-temperature NO2 sensors. Experimentally, a wet-chemical method was used to introduce oxygen vacancies onto SR, leading to forming SR with rich oxygen vacancies (labeled as SR-Vo), which were subsequently deposited with Pd NPs, resulting in preparing Pd NPs loaded SR-Vo hybrids (labeled as Pd-SR-Vo). Impressively, the response value to 1 ppm NO2 of Pd-SR-Vo hybrids reaches to 9.8, which is much higher than that of R-Vo hybrids (5.6) and SR hybrids (3.3). The improvement of sensitivity toward NO2 for Pd-SR-Vo hybrids is attributed to the synergy effect of Pd NPs and oxygen vacancies, including shortening the band gap of Pd-SR-Vo hybrids with raising conduction band level, widening the width of electron depletion layer between SnO2-Vo and RGO, introducing Schottky contact between Pd and SnO2-Vo, improving efficiency for gas sensing reaction. This work not only provides an efficient approach to fabricate high-performance NO2 sensors, but also opens a new avenue for sensing materials design and modification.

Porous In2O3–ZnO nanofiber-based sensor for ultrasensitive room-temperature detection of toluene gas under UV illumination

Toluene gas is hazardous but plays a vital role in several industries. Hence, the detection of toluene gas is important for human health and the environment. In this study, porous In2O3–ZnO nanofibers were prepared via a facile electrospinning method to fabricate a toluene gas sensor. Illumination by ultraviolet light (365 nm) was used to realize the room temperature (RT) operation of the fabricated sensor. The structural properties of the sensor were studied using various characterization techniques. The prepared nanofibers consisted of many sub-nanograins, particularly ZnO and In2O3, and contained numerous pores in-between the nanograins. Consequently, these nanofibers had a large surface area, increasing the probability of contact between the gas and sensor. The prepared sensors were functional at RT under UV illumination and showed excellent toluene-sensing properties. The porous In2O3-appended ZnO-nanofiber-based sensors showed more stable and sensitive response curves than those of the pure ZnO nanofiber–based sensor. Moreover, In2O3-appended ZnO nanofiber sensors could only faintly detect other gases, such as NO2, acetone, ethanol, H2S, and CO gases, indicating that the sensor exhibits highly selective toluene sensing.

Real-Time Monitoring and 3D Mapping of Trace Vapors of Explosive Nitroaromatic Compounds at Room Temperature by Gas-Phase Scanning Electrochemical Microscopy.

Development of sensing technologies for trace vapors of nitroaromatic compounds (NACs) is highly desired due to the toxic and explosive nature of the target molecules. Here, a NAC sensor based on a membraneless ionic liquid electrochemical cell was developed and applied for room-temperature trace vapor detection. Submicrometer working electrode dimensions yielded maximized portability and cost efficiency and extremely short time scales for molecular identification. The nanoprobe exhibited detection limitscomparable to those of state-of-the-art NAC sensors. The most noteworthy feature was the fast response to trace vapors, allowing for real-time detection of NACs without sample pretreatment. The pulled capillary form factor of the developed sensor enabled its application as tip electrodes in gas-phase scanning electrochemical microscopy (SECM). With the degree of freedom in three dimensions, mapping of the differential vapor pressure of NACs was possible, leading to potential application of the probe in sniffing out the source of explosive gas dissemination.

Sensitive Room-Temperature Graphene Photothermoelectric Terahertz Detector Based on Asymmetric Antenna Coupling Structure

A highly sensitive room-temperature graphene photothermoelectric terahertz detector, with an efficient optical coupling structure of asymmetric logarithmic antenna, was fabricated by planar micro-nano processing technology and two-dimensional material transfer techniques. The designed logarithmic antenna acts as an optical coupling structure to effectively localize the incident terahertz waves at the source end, thus forming a temperature gradient in the device channel and inducing the thermoelectric terahertz response. At zero bias, the device has a high photoresponsivity of 1.54 A/W, a noise equivalent power of 19.8 pW/Hz1/2, and a response time of 900 ns at 105 GHz. Through qualitative analysis of the response mechanism of graphene PTE devices, we find that the electrode-induced doping of graphene channel near the metal-graphene contacts play a key role in the terahertz PTE response. This work provides an effective way to realize high sensitivity terahertz detectors at room temperature.

Room-Temperature CMOS Monolithic Resonant Triple-Band Terahertz Thermal Detector

Multiband terahertz (THz) detectors show great application potential in imaging, spectroscopy, and sensing fields. Thermal detectors have become a promising choice because they could sense THz radiations on the whole spectrum. This paper demonstrates the operation principle, module designs with in-depth theoretical analysis, and experimental validation of a room-temperature CMOS monolithic resonant triple-band THz thermal detector. The detector, which consists of a compact triple-band octagonal ring antenna and a sensitive proportional to absolute temperature (PTAT) sensor, has virtues of room-temperature operation, low cost, easy integration, and mass production. Good experimental results are obtained at 0.91 THz, 2.58 THz, and 4.2 THz with maximum responsivities of 32.6 V/W, 43.2 V/W, and 40 V/W, respectively, as well as NEPs of 1.28 μW/Hz0.5, 2.19 μW/Hz0.5, and 2.37 μW/Hz0.5, respectively, providing great potential for multiband THz sensing and imaging systems.

Cadmium Magnesium Telluride for Next-Generation X-Ray Free Electron Laser, Synchrotron, and Many Other Applications

We developed a picosecond photodetector based on our Bridgman-grown and specially engineered cadmium magnesium telluride (Cd <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{\mathrm {1-x}}$ </tex-math></inline-formula> MgxTe) single crystal that is sensitive to both optical and X-ray pulses for coarse timing in free-electron laser applications. Cd <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{\mathrm {1-x}}$ </tex-math></inline-formula> MgxTe is a widebandgap semiconductor with potential applications, not only in optoelectronics, but also in particle physics as an intense pulse radiation detector for bremsstrahlung, X-ray/gamma-ray radiation, thermal neutrons, and medical imaging. For femtosecond optical and X-ray cross-correlation, the material must have a very short lifetime, a condition that is opposite to that required for nuclear spectroscopy applications. At the same time, the material also needs to have a very low bulk leakage current, in the 10–90 nA range for voltages to even 1000 V. Hence, the ability to tailor or engineer the material is very crucial. Picosecond response and the crystal growth of this specially engineered Cd <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{\mathrm {1-x}}$ </tex-math></inline-formula> MgxTe material are presented. Other characterization and transient measurements are discussed along with room-temperature semiconductor detector performance for other nuclear radiation detection applications.

Room Temperature Detection of Chlorpyrifos Using Thermally Oxidized Manganese and Copper Thin Films

The usage of pesticides has increased rapidly over the past three decades to boost crop production and meet the global food demand. According to UN FAO, about 66% of the countries have reported an average increase in pesticide consumption of about 1.85 kg hectare−1 between 1990 and 2019. Chlorpyrifos is a widely used but hazardous pesticide, popular for domestic and agricultural applications. Real-time monitoring of Chlorpyrifos is necessary for its safe application due to its toxicity, even at the residue level. In this work, an attempt has been carried out to detect chlorpyrifos at room temperature using thermally oxidized manganese and copper thin films. Thermal oxidation of thin films has been carried out under air ambient at different temperatures ranging from 400 °C to 550 °C for manganese and 500 °C to 800 °C for copper thin films. Morphological investigation depicts nanobar-like morphology and irregular-sized clusters for various oxidation temperatures of manganese oxide thin films, and granular-like morphology with an increase in grain size has been observed for increasing oxidation temperature. Structural investigation using the XRD technique depicts the evolution of various phases of manganese oxide thin film and a single monoclinic phase for copper oxide thin film. Further, the RMS roughness of the manganese and copper film was found to vary differently with the rise in oxidation temperature. Copper oxide thin films have shown higher chlorpyrifos sensing response with sensitivity than thermally oxidized manganese thin films better sensing response towards chlorpyrifos. The sensitivity at room temperature is found to be around 30 and 250 for manganese oxide and copper oxide thin films, respectively.

Silver Anchored Polyaniline@Molybdenum Disulfide Nanocomposite (Ag/Pani@MoS2) for Highly Efficient Ammonia and Methanol Sensing under Ambient Conditions: A Mechanistic Approach.

We report the synthesis of silver anchored and para toluene sulfonic acid (pTSA) doped polyaniline/molybdenum disulfide nanocomposite (pTSA/Ag-Pani@MoS2) for highly reproducible room temperature detection of ammonia and methanol. Pani@MoS2 was synthesized by in situ polymerization of aniline in the presence of MoS2 nanosheets. The chemical reduction of AgNO3 in the presence of Pani@MoS2 led to the anchoring of Ag to Pani@MoS2 and finally doping with pTSA produced highly conductive pTSA/Ag-Pani@MoS2. Morphological analysis showed Pani-coated MoS2 along with the observation of Ag spheres and tubes well anchored to the surface. Structural characterization by X-ray diffraction and X-ray photon spectroscopy showed peaks corresponding to Pani, MoS2, and Ag. The DC electrical conductivity of annealed Pani was 11.2 and it increased to 14.4 in Pani@MoS2 and finally to 16.1 S/cm with the loading of Ag. The high conductivity of ternary pTSA/Ag-Pani@MoS2 is due to Pani and MoS2 π-π* interactions, conductive Ag, as well as the anionic dopant. The pTSA/Ag-Pani@MoS2 also showed better cyclic and isothermal electrical conductivity retention than Pani and Pani@MoS2, owing to the higher conductivity and stability of its constituents. The ammonia and methanol sensing response of pTSA/Ag-Pani@MoS2 showed better sensitivity and reproducibility than Pani@MoS2 owing to the higher conductivity and surface area of the former. Finally, a sensing mechanism involving chemisorption/desorption and electrical compensation is proposed.

Silicon Oxy-Nitride for the Low Refractive Index Layers in the Mirror Coatings of the Cryogenic Laser Interferometer Gravitational Waves Detector.

The low refractive index layers in the mirror coatings of the room-temperature laser interferometer gravitational waves detectors are silica deposited by the ion beam sputter method. However, the silica film suffers from the cryogenic mechanical loss peak, hindering its application for the next generation detector operated at cryogenics. New low refractive index materials need to be explored. We study amorphous silicon oxy-nitride (SiON) films deposited using the method of plasma-enhanced chemical vapor deposition. By changing the N_{2}O/SiH_{4} flow rate ratio, we can tune the refractive index of the SiON smoothly from nitridelike to silicalike of ∼1.48 at 1064nm, 1550nm, and 1950nm. Thermal anneal reduced the refractive index down to ∼1.46 and effectively reduced the absorption and cryogenic mechanical loss; the reductions correlated with the N─H bond concentration decrease. Extinction coefficients of the SiONs at the three wavelengths are reduced down to 5×10^{-6}∼3×10^{-7} by annealing. Cryogenic mechanical losses at 10K and 20K (for ET and KAGRA) of the annealed SiONs are significantly lower than the annealed ion beam sputter silica. They are comparable at 120K (for LIGO-Voyager). Absorption from the vibrational modes of the N─H terminal-hydride structures dominates over the absorption from other terminal hydrides, the Urbach tail, and the silicon dangling bond states in SiON at the three wavelengths.

Towards Extended Gate Field Effect Transistor-Based Radiation Sensors: Impact of Thicknesses and Radiation Doses on Al-Doped Zinc Oxide Sensitivity

Radiation measurements are critical in radioanalytical, nuclear chemistry, and biomedical physics. Continuous advancement in developing economical, sensitive, and compact devices designed to detect and measure radiation has increased its capability in many applications. In this work, we presented and investigated the performance of a cost-effective X-ray radiation detector based on the extended gate field effect transistors (EGFET). We examined the sensitivity of Al-doped Zinc oxide (AZO) of varying thicknesses, fabricated by chemical bath deposition (CBD), following X-ray irradiation with low and high doses. EGFETs were used to connect samples for their detection capabilities. As a function of the absorbed dose, the response was analyzed based on the threshold voltage shift, and the sensitivity of each device was also evaluated. We demonstrated that thin films are less sensitive to radiation than their disk-type EG devices. However, performance aspects of the devices, such as radiation exposure sensitivity and active dosage region, were found to be significantly reliant on the composition and thickness of the materials used. These structures may be a cost-effective alternative for real-time, room-temperature radiation detectors.

Positional correction of a 3D position-sensitive virtual Frisch-grid CZT detector for gamma spectroscopy and imaging based on a theoretical assumption

The virtual Frisch-grid method for room-temperature radiation detectors has been widely used because of its simplicity and high performance. Recently, side electrodes were separately attached to each surface of the detectors instead of covering the entire detector surface with a single electrode. The side-electrode structure enables the measurement of the three-dimensional (3D) gamma-ray interaction in the detector. The positional information of the interaction can then be utilized to precisely calibrate the response of the detector for gamma-ray spectroscopy and imaging. In this study, we developed a 3D position-sensitive 5 × 5 × 12 mm3 cadmium-zinc-telluride (CZT) detector and applied a flattening method to correct detector responses. Collimated gamma-rays incident on the surface of the detector were scanned to evaluate the positional accuracy of the detection system. Positional distributions of the radiation interactions with the detector were imaged for quantitative and qualitative evaluation. The energy spectra of various radioisotopes were measured and improved by the detector response calibration according to the calculated positional information. The energy spectra ranged from 59.5 keV (emitted by 241Am) to 1332 keV (emitted by 60Co). The best energy resolution was 1.06% at 662 keV when the CZT detector was voxelized to 20 × 20 × 10.

Rare earth(Sm3+) doped CoCr2O4 ceramics sensor towards room temperature detection of greenhouse methane gas

Increased fossil fuel consumption in today's high-tech society has led to a rise in atmospheric concentrations of greenhouse gases that must be a mitigated. To get there, we need sensors that can report on atmospheric concentrations of greenhouse gases. Rare earths are used in the renewable energy technologies such as greenhouse gases, wind turbines, batteries, catalysts and electric cars. Current mining. Focusing greenhouse gases in mind we have synthesized samarium (Sm3+) doped CoCr2O4 by solution combustion method. Samples was characterized by X-ray diffractogram to know about crystallinity and phase formation. Once we know about the phase the same samples were subjected to characterize scanning electronic microscopy to know the morphology. Fourier transform infrared spectroscopy, analysis are used to examine the stretching vibration bonds. The methane gas sensing performance of the CoCr2-xSmxO4 samples are examined for different concentration of methane gas. The methane gas sensing responses with a function of applied methane gas concentrations varies form 50 ppb–500 ppb levels. The x = 0.02 exhibits an enhanced gas sensing performance 90% in contrast with the pure x = 0.00 sample in the order of 16%. The higher gas sensitivity value in sample is due to the enhanced change in resistance value in the existence of methane gas. Further quick response and recovery times were observed in the order of 65 and 86 s. The sensor created in this study has the potential to be used to detect low amounts of greenhouse methane gas because to its good conductivity, superior sensing capability, and improved mechanical qualities. The importance of these materials as low power consumption gas sensors at ambient temperature is demonstrated by the increased sensing response and improved selectivity toward methane. It is possible that the establishment of a conductive network and synergetic - connections among the various phases of the hybrid system are responsible for the better sensing behaviour of the composite. These interactions help facilitate the delocalization of electrons.

Latest developments in room-temperature semiconductor neutron detectors: Prospects and challenges

Latest developments in room-temperature semiconductor neutron detectors: Prospects and challenges

An in situ synthesis of polyaniline/reduced graphene oxide nanocomposite flexible thin film on PET for the room temperature detection of trace level ammonia at ppb level

An in situ synthesis of polyaniline/reduced graphene oxide nanocomposite flexible thin film on PET for the room temperature detection of trace level ammonia at ppb level

Facile fabrication of nanoflower-like WO3/WS2 heterojunction for highly sensitive NO2 detection at room temperature.

Realizing efficient detection of ultra-low concentrations of hazardous gases contributes to air pollution monitoring, ecosystem and human health protection. Herein, we firstly fabricated the nanoflower-like WO3/WS2 composites by a facile process to highly sensitively detect NO2 at room temperature. The WO3 content in the WO3/WS2 composites can be adjusted by altering the calcination temperature, and the WO3 nanoparticles disperse uniformly on the WS2 surface, forming the WO3/WS2 heterojunction. The room-temperature responses of WO3/WS2 composites gradually climb with the NO2 concentration increasing from 0.005 to 5ppm, and the WW-280 and WW-300 composites possess the optimal gas sensitivity when the NO2 concentrations are lower and higher than 100 ppb, respectively. In particular, the two WO3/WS2 composites present the limitation of detection (LOD) of ≤5 ppb, and they exhibit the excellent selectivity, good reproducibility and long-term stability towards NO2. A possible gas sensing mechanism was also proposed from the point of views of gas adsorption, redox reactions and electron transfer. The appropriate WO3 content and molar ratio of hexagonal to monoclinic WO3, and the formation of WO3/WS2 p-n heterojunction can contribute to the high sensitivity of WO3/WS2 composite to various concentrations of NO2. This work offers a promising gas sensing material for room-temperature detection to low concentrations of NO2.

Paper-Based Hydrogen Sensors Using Ultrathin Palladium Nanowires

Hydrogen (H2), as a chemical energy carrier, is a cleaner alternative to conventional fossil fuels with zero carbon emission and high energy density. The development of fast, low-cost, and sensitive H2 detection systems is important for the widespread adoption of H2 technologies. Paper is an environment-friendly, porous, and flexible material with great potential for use in sustainable electronics. Here, we report a paper-based sensor for room-temperature H2 detection using ultrathin palladium nanowires (PdNWs). To elucidate the sensing mechanism, we compare the performance of polycrystalline and quasi-single-crystalline PdNWs. The polycrystalline PdNWs showed a response of 4.3% to 1 vol % H2 with response and recovery times of 4.9 and 10.6 s, while quasi-single-crystalline PdNWs showed a response of 8% to 1 vol % H2 with response and recovery times of 9.3 and 13.0 s, respectively. The polycrystalline PdNWs show excellent selectivity, stability, and sensitivity, with a limit of detection of 10 ppm H2 in air. The fast response of ultrathin polycrystalline PdNW paper-based sensors arises from the synergistic effects of their ultrasmall diameter, high-index surface facets, strain-coupled grain boundaries, and porous paper substrate. This paper-based sensor is one of the fastest chemiresistive H2 sensors reported and is potentially orders of magnitude less expensive than current state-of-the-art H2-sensing solutions. This brings low-cost, room-temperature chemiresistive H2 sensing closer to the performance of ultrafast optical sensors and high-temperature metal oxide-based sensors.

Room Temperature Humidity Tolerant Xylene Sensor Using a Sn-SnO2 Nanocomposite

Xylene is one of the representative indoor pollutants, even in ppb levels, that affect human health directly. Due to the non-polar and less reactive nature of xylene, its room temperature detection is challenging. This work demonstrates a metallic tin-doped Sn-SnO2 nanocomposite under controlled pH conditions via a simple solvothermal route. The Sn nanoparticles are uniformly distributed inside the SnO2 nanospheres of ∼70 nm with a high specific surface area of 118.8 m2/g. The surface of the Sn-SnO2 nanocomposite exhibits strong affinity toward benzene, toluene, ethylbenzene, and xylene (BTEX) compared to other polar volatile organic compounds (VOCs) such as ethanol, acetone, isopropyl alcohol, formaldehyde, and chloroform tested in this study. The sensor's response is highest for xylene among BTEX molecules. Under ambient room temperature conditions, the sensor exhibits a linear response to xylene in the 1-100 ppm range with a sensitivity of ∼255% at 60 ppm within ∼1.5 s and recovers in ∼40 s. The sensor is hardly affected by humidity variations (40-70%), leading to enhanced reliability and repeatability under dynamic environmental conditions. The meso and microporous nanosphere morphology act as a nanocontainer for non-polar VOCs to diffuse inside the nanostructures, providing easy accessibility. The metallic Sn increases the affinity for less reactive xylene at room temperature. Thus, the nanocatalytic Sn-SnO2 nanocomposite is an active gas/VOC sensing material and provides an effective solution for sensing major indoor pollutants under humid conditions.

Laser-Patterned Porous Carbon/ZnO Nanostructure Composites for Selective Room-Temperature Sensing of Volatile Organic Compounds

The development of mobile, noninvasive, and portable sensor technologies for diagnostics and emission control is highly demanded. For that purpose, laser carbonization is studied as a tool to produce responsive carbon materials from inexpensive organic precursors for the room-temperature selective detection of volatile organic compounds (VOCs) applicable in future sensor array-based devices. To increase the response of intrinsically low-responsive laser-patterned carbons (LP-C) to analytes in the gas phase, we tested carbonization in the presence of nanoscale ZnO precursors in primary inks. Following the addition of a zinc salt, Zn(NO3)2, a noticeable 43-fold increase in the sensor response (ΔR/R0 = −21.5% toward 2.5% acetone) was achieved. This effect is explained by a significant increase in the measurable surface area up to ∼700 m2·g–1 due to the carbothermic reduction supported by the in situ formation of ZnO nanoparticles. Varying Zn concentrations or the addition of as-prepared ZnO nanorods lead to different surface properties like the surface area, porosity, and polarity of LP-C. A predominant effect of the surface polarity on the selectivity toward different analytes of the sensors during physisorption, e.g., acetone vs toluene, was identified and tested. The best-performing LP-C sensors were finely characterized by transmission/scanning electron microscopies and X-ray photoelectron/energy-dispersive X-ray/Raman spectroscopies.

Highly Selective Room Temperature Detection of NH3 and NOx Using Oxygen-Deficient W18O49-Supported WS2 Heterojunctions

In this paper, we reported the controlled synthesis of tungsten disulfide/reduced tungsten oxide (WS2/W18O49) heterojunctions for highly efficient room temperature NOx and ammonia (NH3) sensors. X-ray diffraction analysis revealed the formation of the oxygen-deficient W18O49 phase along with WS2. Field-emission scanning electron microscopy and transmission electron microscopy displayed the formation of WS2 flakes over W18O49 nanorods. X-ray photoelectron spectroscopy showed the presence of tungsten in W4+, W5+, and W6+ oxidation states corresponding to WS2 and W18O49, respectively. The WS2/W18O49 heterojunction sensor exhibited sub-ppm level sensitivity to NOx and NH3 at room temperature. The heterojunction sensor detected 0.6 ppm NOx and 0.5 ppm NH3, with a corresponding response of 7.1 and 3.8%, respectively. The limit of detection of the sensor was calculated to be 0.05 and 0.17 ppm for NH3 and NOx, respectively. The cyclic stability test showed that the sensor exhibited high stability even after 24 cycles for the detection of NH3 and 14 cycles for NOx. Compared to pristine WO3 and WS2, the WS2/W18O49 heterojunction showed high selectivity toward NOx and NH3. The results could be useful for the development of room temperature NOx and NH3 sensors.

Room-Temperature Sub-ppm Detection and Machine Learning-Based High-Accuracy Selective Analysis of Ammonia Gas Using Silicon Vertical Microwire Arrays

The potential applications of silicon microwire materials in monitoring gases have not been fully exploited. Uniform silicon vertical microwire arrays (Si VMWA) are fabricated using a metal-assisted chemical etching process after optimizing the conditions. The characteristics and responses of Si VMWA-based sensors with different diameters to ammonia gas (NH3) are investigated in both air and nitrogen environments. The sensing mechanism of the sensor to NH3 is discussed to clarify the response in different environments. The sensor exhibits a linear response to a wide range of NH3 concentrations (4%@2 ppm–122%@500 ppm) at room temperature and even shows a distinct response at 200 ppb of NH3. In addition, it demonstrates great repeatability/reversibility and moderate selectivity to ammonia gas against other gases (nitrogen dioxide, toluene, and isobutane). Furthermore, machine learning-based principal component analysis and random forest algorithms enable us to discriminate NH3 from other possible interfering gases and predict gas concentration with an accuracy of over 95%. Thus, our approach using the Si VMWA-based sensor with machine learning-based data analysis represents a significant step toward the environmental sensing of specific chemical analytes in the household and industries.