Acetone Gas Sensor Research Articles

Acetone Gas Sensor with SnO2-Modified MoS2 Nanospheres

Abstract This study employed a hydrothermal method to prepare molybdenum disulfide (MoS2) and a two-step hydrothermal process to synthesize tin oxide (SnO2)-modified MoS2 nanostructured materials. The manufacturing process is simple and cost-effective, and the produced materials were analyzed using various techniques to confirm their high purity and crystallinity. The SnO2-modified MoS2 nanostructured materials were then utilized to fabricate acetone gas sensors. The high surface area of MoS2, coupled with the heterojunction interfaces formed by SnO2 modification, enhances the performance of the gas sensor. At 150°C, the sensor exhibits a remarkable response of 37.1% to 100 ppm acetone gas. The dynamic response, including response and recovery times, is also impressive. Gas sensors developed with this material can effectively detect acetone concentrations in various environmental conditions.

Insights into Target Gas-Oxygen Interactions in Highly Sensitive Gas Sensors Using Data-Driven Methods.

In the gas-sensing mechanism of a metal-oxide-semiconductor (n-type) gas sensor, oxygen adsorption or desorption on the oxide surface leads to an increase or decrease in the resistance of the gas sensor system. Additionally, oxygen can be adsorbed again at the location where initially adsorbed oxygen reacted with the target gas. Thus, the adsorption-desorption equilibrium of the reducing gas on the oxide surface is a significant factor in determining the sensitivity and reaction rate. In particular, for ultralow-concentration gas measurements, the relative concentration of oxygen was very high. To design an ultrasensitive gas sensor, not only the reaction of the target gas but also the competing reaction between the target gas and oxygen must be considered. Although qualitative investigations of these complex relationships have been performed according to the gas concentration and flow rate, reliable quantitative results are limited. In this study, a quantitative approach was used to understand the correlation between oxygen and a target gas by applying data analysis methods. We investigated the behavior of oxygen and the target molecules depending on the gas concentration and flow rate using the parts per billion level of the acetone gas sensor. Initial response data according to various detection conditions were processed using principal component analysis and K-means clustering; as a result, four types of reaction behaviors were inferred for 15 types of reaction conditions. Furthermore, the response time, depending on the detection conditions, can be distinguished using the suggested categorization. Our investigation suggests a possibility beyond simple optimization through the data analysis of the gas-sensing results.

Ultrasensitive Acetone Gas Sensor Based on a K/Sn-Co3O4 Porous Microsphere for Noninvasive Diabetes Diagnosis.

The detection of acetone in human exhaled breath is crucial for the noninvasive diagnosis of diabetes. However, the direct and reliable detection of acetone in exhaled breath with high humidity at the parts per billion level remains a great challenge. Here, an ultrasensitive acetone gas sensor based on a K/Sn-Co3O4 porous microsphere was reported. The sensor demonstrates a detection limit of up to 100 ppb, along with excellent repeatability and selectivity. Remarkably, without the removal of water vapor from exhaled breath, the sensor can accurately distinguish diabetic patients and healthy individuals according to the difference in acetone concentrations, demonstrating its great potential for diabetes diagnosis. The enhanced sensitivity of the sensor is attributed to the increased oxygen adsorption on the material surface due to K/Sn codoping and the stronger coadsorption of Sn-K atoms to acetone molecules. These findings shed light on the mechanisms underlying the sensor's improved performance.

Porous PDMS-ZnO Wearable Gas Sensor for Acetone Biomarker Detection and Breath Analysis.

In response to the growing demand for global health monitoring, we report a nonintrusive health detection method using a compact, conformal wearable ultraviolet (UV)-assisted gas-sensing system based on an intrinsically flexible porous polydimethylsiloxane (PDMS)-zinc oxide (ZnO) composite layer (PPZL) for the breath acetone (BrAce) detection and breath event analysis. The enhanced acetone response is attributed to the synergistic effect of UV irradiation and the high surface area of the porous structure, which also improves the mechanical robustness. The UV-assisted wearable sensor reliably detects acetone concentrations ranging from 1 to 100 ppm at room temperature under 4.05 mW/cm2 UV intensity, even under mechanical strains such as a bending radius of 5 mm and 60% tensile strain. It accurately analyzes different breathing patterns (12-20 breaths per minute) and BrAce concentrations, maintaining a stable performance over 20 days with less than 5% signal degradation. The sensor exhibits response and recovery times of average 110-150 and 130-180 s, respectively, and maintains a consistent 3 ppm BrAce response under varying humidity levels up to 70% relative humidity, ensuring accurate detection of BrAce concentrations during real-world breath tests. Additionally, the sensor targets only specific gases, and the sensor's selectivity is not a key concern. This flexible acetone gas sensor offers a portable solution for health management and a fabrication method for designing flexible metal oxide materials.

Nitrogen-Doped Carbon Quantum Dots Activated Dandelion-Like Hierarchical WO3 for Highly Sensitive and Selective MEMS Sensors in Diabetes Detection.

High sensitivity, low concentration, and excellent selectivity are pronounced primary challenges for semiconductor gas sensors to monitor acetone from exhaled breath. In this study, nitrogen-doped carbon quantum dots (N-CQDs) with high reactivity were used to activate dandelion-like hierarchical tungsten oxide (WO3) microspheres to construct an efficient and stable acetone gas sensor. Benefiting from the synergistic effect of both the abundant active sites provided by the unique dandelion-like hierarchical structure and the high reaction potential generated by the sensitization of the N-CQDs, the resulting 16 wt % N-CQDs/WO3 sensor shows an ultrahigh response value (Ra/Rg = 74@1 ppm acetone), low detection limit (0.05 ppm), outstanding selectivity, and reliable stability to acetone at the optimum working temperature of 210 °C. Noteworthy that the N-CQDs facilitate the carrier migration and intensify the reaction between acetone and WO3 during the sensing process. Considering the above advantages, N-CQDs as a sensitizer to achieve excellent gas-sensitive properties of WO3 are a promising new strategy for achieving accurate acetone detection in real time and facilitating the development of portable human-exhaled gas sensors.

Liquid crystal gel-based acetone sensor using correlated laser speckles

Acetone, a common volatile organic compound (VOC), poses health risks even at low concentrations. Current acetone sensors are costly and require specialized equipment and expertise. This work develops a novel vapor sensor for determining acetone vapor concentration using the speckle patterns generated by liquid crystal gels (LCGs). The vapor sensor comprises a LCG film prepared by the phase separation of a mixture containing polystyrene microspheres and liquid crystals (LCs). The orientation of the LC molecules changes when the LCG film is exposed to an acetone vapor environment, altering the equivalent refractive indices of the LC domains. This leads to a change in the scattering state of the LCG film under laser illumination, forming different speckle patterns. The concentration of acetone vapor is determined by calculating the correlation coefficient of the speckle images, where the sensitivity and limit of detection of the sensor are 4×10-4 ppm-1 and 754.05 ppm, respectively. The developed correlated laser speckle-based optical system is simpler, less expensive, and more stable than traditional LC film vapor sensors. This acetone gas sensor has potential applications in industrial and indoor air quality testing.

Construction of a novel Mott-Schottky heterostructure gas sensor g-C3N4/SnO2 with layered nanorods array for high-sensitivity acetone detection

Developing exhaled acetone sensors with high performance can be effectively applied to the medical diagnosis and the health monitoring. Herein, a two-dimensional (2D) layered graphitic carbon nitride (g-C3N4) with tunable electronic structure, abundant edge sites, and high stability is proposed, and it is further coupled with stannic oxide (SnO2) by one-step hydrothermal approach to construct a Mott-Schottky heterostructure with layered nanorods array. The exceptional response of the as-fabricated g-C3N4/SnO2 gas sensor to 50 ppm acetone at 100 °C is four times higher than that of the pristine SnO2 sensor. Additionally, the g-C3N4/SnO2 sensor’s remarkable selectivity, long-term stability against acetone gas, and detection limit of 250 ppb are exhibited. The unique hierarchical design and the Mott-Schottky heterostructure creation which validated by electrochemical study, may be in charge of the enhanced acetone sensing capabilities of g-C3N4/SnO2 gas sensor. This work will provide a concise and effective avenue to construct hierarchical composite with Mott-Schottky heterostructure for high-performance acetone gas sensor.

Deep-Learning-Based Blood Glucose Detection Device Using Acetone Exhaled Breath Sensing Features of α-Fe2O3-MWCNT Nanocomposites.

Owing to the correlation between acetone in human's exhaled breath (EB) and blood glucose, the development of EB acetone gas-sensing devices is important for early diagnosis of diabetes diseases. In this article, a noninvasive blood glucose detection device through acetone sensing in EB, based on an α-Fe2O3-multiwalled carbon nanotube (MWCNT) nanocomposite, was successfully developed. Different amounts of α-Fe2O3 were added to the MWCNTs by a simple solution method. The optimized acetone gas sensor showed a response of 5.15 to 10 ppm acetone gas at 200 °C. Also, the fabricated sensor showed very good sensing properties even in an atmosphere with high relative humidity. Since the EB has high humidity, the proposed sensor is a promising device to exactly detect the amount of acetone in EB with high humidity. The sensor was powered by a 3200 mAh battery with the possibility of charging using mains electricity. To increase the reliability and calibration of the sensing device, a practical test was taken to detect acetone EB from 50 volunteers, and a deep learning algorithm (DLA) was used to detect the effect of various factors on the amount of acetone in each person's acetone EB. The proposed device with ±15 errors had almost 85% correct responses. Also, the proposed device had excellent response, short response time, good selectivity, and good repeatability, leading it to be a suitable candidate for noninvasive blood glucose sensing.

Enhancement of the Sensing Properties of Chitosan Films as an Acetone Gas Sensor with the Addition of Tin Oxide (SnO2)

Enhancement of the Sensing Properties of Chitosan Films as an Acetone Gas Sensor with the Addition of Tin Oxide (SnO2)

UV photosensitized N-CQDs@In2O3 ordered porous film elaborated optical fiber acetone gas sensor with ppb-level at room temperature

An optical fiber acetone gas sensor based on N-CQDs@In2O3 porous ordered thin film is proposed. The probe adopts the hollow malposition structure (HMS) to excite the evanescent field on the surface of hollow-core fiber (HCF). N-CQDs@In2O3 porous and ordered thin film was formed on the surface of optical fiber after calcining polystyrene (PS) microspheres at high temperature. The experimental results reveal the ultraviolet (UV) sensitization function for the proposed sensor at room temperature. The enhanced sensitivity is 7.1 pm/ppm, which is ∼5.9 times of the spiritual density of unsensitized sensor. In addition, the sensor has a limit of detection (LOD) of 500 ppb and excellent time response characteristics (response time 6.2 s and recovery time 7.1 s). The sensitization mechanism of N-CQDs to In2O3 is explained by the results of the universal density function (DFT). The frontier electron orbital studies show that N-CQDs@In2O3 has more abundant electron clouds. The good moisture resistance enables its stable performance in humid environment. UV sensitization is an effective way to improve the sensitivity of optical fiber gas sensor, which is of great significance for detecting the acetone gas with ultra-low concentration.

Enhanced acetone gas sensors based on Pt-modified Co3O4/CoMoO4 heterojunctions

The focus of this work is to develop a sensitive and reliable acetone gas sensor using the Pt-modified Co3O4/CoMoO4 heterojunction derived from metal-organic frameworks (MOFs). Pt-loaded Co3O4/CoMoO4 heterojunction was successfully prepared by the surface redox method, and the composites exhibited high sensitivity and selectivity for acetone with a low detection limit. By modifying the Co3O4/CoMoO4 material with platinum loading, the sensor achieved a response of 24.12 to 20 ppm acetone, which was significantly better than that of the pure Co3O4/CoMoO4 heterojunction. This work not only improves acetone detection strategies, but also enhances the potential for industrial and medical VOC monitoring applications.

Defect-enabled room-temperature acetone gas sensors based on Zn-doped cauliflower-like bismuth oxide

Metal oxide-based gas sensors have promising advantages, such as low cost and high sensitivities, but the high working temperature (150°C–300 °C) hinders their practical applications. Herein, this study demonstrated a Zinc (Zn)-doped approach to achieve defect-enabled room-temperature acetone gas sensors based on bismuth oxide (Bi2O3) thin film. Through a simple chemical bath deposition method, the varying substitutional doping of zinc (2 wt% to 8 wt%) can induce the morphological transformation of Bi2O3 nanosheets to a cauliflower-like nanostructure, leading to enhanced surface area and active sites. The incorporation of Zn ions can result in oxygen vacancies in the Bi2O3 lattice and the rising of the depletion layer, facilitating the interaction toward acetone molecules at ambient temperatures, leading to an increment of response ∼6. The Zn-doped cauliflower-like Bi2O3 electrode exhibits a superior sensing performance of acetone gas with a low detection limit of 1 ppm and high stability over 90 days. This work underscores the potential of controlled doping of Zn for oxygen vacancy-riched Bi2O3 thin film as a promising room-temperature acetone gas sensor, offering new avenues for the detection of hazardous gases with improved sensitivity.

Acetone Gas Sensing Using a Hybrid Mid-Infrared Fluoride Fiber Laser

Acetone Gas Sensing Using a Hybrid Mid-Infrared Fluoride Fiber Laser

Temperature and humidity effects on the acetone gas sensing of pristine and Pd-doped WO3 clusters: A transition state theory study.

The performance of pristine and Pd-doped WO3 acetone gas sensors is calculated theoretically and compared with available experimental results. Temperature, humidity, and acetone concentration variation are considered in the present work. Transition state theory calculates Gibbs free energy of transition, including its components enthalpy and entropy of transition or activation. The variation of Pd doping concentration is used to obtain the maximum response and lowest response time for the optimum performance of the gas sensor. The present theory considers the reduction of acetone gas concentration as acetone reaches its autoignition temperature. Acceptable agreement between theory and experiment is obtained. The acceptance includes the decrease of Gibbs free energy with doping percentage, variation of temperature exponent to the power twelve in the considered reactions, and reduction of response time with the increase of temperature. Density functional theory at the B3LYP level is used. 6-311G** basis set (for O atoms) and SDD (for heavy Pd and W atoms) are used to optimize the structures examined in the present work. The Gaussian 09 program and accompanying software were used to perform the current tasks.

Dual functionalized Co3O4 porous cages with Pd and Co-MOF for acetone gas sensing under high humidity

Metal oxide semiconductor (MOS) gas sensors play a crucial role in gas sensors. However, the effect of higher ambient humidity on the sensitivity of MOS gas sensors is still largely an unsolved problem, limiting the application areas of sensors. In this work, an ultra-stable and sensitive acetone gas sensor based on dual functionalized Co3O4 porous cages with Pd and Co-MOF at high humidity is reported. The dual functionalized porous cages are made of MOF-derived Co3O4 porous cages substrate, Pd particles and hydrophobic Co-MOF coatings. The prepared porous cages composite exhibits humidity-independent and highly sensitive gas-sensing behavior to acetone under 70–90 % relative humidity (RH). The results indicate that the hydrophobic Co-MOF coatings not only offer excellent anti-humidity, but also show the ability of enrichment of low concentration acetone gas molecules, thus improving the sensitivity and response time of acetone detection. Meanwhile, due to the electronic spillover effect of Pd, porous cages composite possesses remarkable properties of high sensitivity, short response and recovery time, as well as low working temperature. The unique sensing characteristic makes the dual functionalized porous cages composite sensor a potential candidate for reliable noninvasive diagnosis of diabetes via exhaled breath analyses.

Highly sensitive acetone gas sensor based on gold nanoparticles modified W18O49 porous polymeric spheres

Highly sensitive acetone gas sensor based on gold nanoparticles modified W18O49 porous polymeric spheres

Oxygen vacancy-mediated metal-organic gel-derived α-Fe2O3 for anomalous acetone sensing behavior

The development of acetone gas sensors with high sensitivity, low detection limits and scalability holds significant importance for industrial production safety and disease diagnosis. Herein, oxygen vacancies-enriched α-Fe2O3 nanoparticles (M-Fe2O3 NPs) were synthesized through a novel metal-organic gel template strategy. Gas sensing experiments revealed that the prepared M-Fe2O3 sensor displayed unique p-type semiconductor behavior, distinct from the n-type commercial α-Fe2O3 (C-Fe2O3) sensor. Moreover, the sensor demonstrated excellent acetone sensing performance, including high response (2.6 @ 20 ppm), low detection limit (0.5 ppm), remarkable repeatability and selectivity, even under 80% relative humidity (RH), displaying impressive response and recovery properties. The enhanced p-type sensing properties of the M-Fe2O3 sensor were attributed to oxygen vacancies facilitating inversion (hole) layer formation and accelerating chemical reactions on the sensing materials surface, as evidenced by gas sensing performance data and O2-TPD characterization. Finally, the feasibility of preliminary diabetes diagnosis was demonstrated by detecting acetone levels in human exhaled breath. This work not only presents a straightforward approach for designing oxygen vacancies-enriched metal oxides but also has potential applications in constructing high-performance acetone sensing systems for diabetes diagnosis.

ErFeO3/α-Fe2O3 nanocomposites derived from MIL-100(Fe) for acetone sensing

Acetone, a flammable and volatile liquid, is toxic and can affect human well-being. Additionally, its presence in exhaled air can indicate the state of human respiratory health. Therefore, the investigation of an acetone gas sensor holds significant urgency in the realm of scientific research. Metal-organic frameworks (MOFs) exhibit significant promise in the field of gas detection due to their extensive surface areas, remarkable porosity, and the inclusion of unsaturated metallic sites. The study conducted the preparation of ErFeO3/α-Fe2O3 nanocomposites through impregnation and oxidation roasting methods. EF21 (MEr(NO3)3∙6H2O:MMIL-100(Fe) = 2:1) exhibited a large surface area of 43.7 m2/g and a high abundant oxygen vacancy of 12.5 %. Gas sensing experiments revealed that the EF21-based gas sensor exhibited a strong response of 55 towards 100 ppm acetone, with a low detection limit of 2 ppm (S = 3.3). Notably, the sensor demonstrated excellent selectivity towards acetone over other volatile organic compounds (e.g., ethanol, methanol, ammonia, ether, and toluene) in gas selectivity tests. Moreover, the EF21-based gas sensor maintained its responsiveness to acetone even under high relative humidity conditions (RH:90 %, S = 27) and demonstrated stability over a 15-day long-term test. The study provided a comprehensive explanation of the gas sensing mechanism responsible for the enhanced performance observed in ErFeO3/α-Fe2O3 through detailed analyses.

High sensitivity low-temperature ethanol and acetone gas sensors based on silver/titanium oxide decorated laser-induced graphene

High sensitivity low-temperature ethanol and acetone gas sensors based on silver/titanium oxide decorated laser-induced graphene

Enhanced acetone detection for non-invasive diabetes monitoring by atomic layer deposited WO3 nanoparticle on hierarchical In2O3 particles

This study addressed the critical need for non-invasive monitoring of diabetes by proposing an acetone gas sensor based on hierarchical In2O3 with atomic layer deposition (ALD)-deposited WO3 nanoparticles. The sensor fabrication involved a carefully designed process, leveraging ALD to control WO3 deposition, ensuring uniform distribution, and mitigating agglomeration. The resulting composite exhibited enhanced sensitivity, making it promising for detecting acetone, a key biomarker for diabetes. Material synthesis, including hydrothermal formation of In2O3 hierarchy particles and ALD of WO3, was meticulously conducted. Comprehensive characterizations, involving SEM, TEM, EDX, XRD, XPS, and BET, validated the successful synthesis and deposition. The sensor’s response to varying acetone concentrations (50–2000 ppb) was systematically investigated, revealing a positive correlation. The In2O3/WO3–2 sensor exhibited the highest sensitivity, attributed to the catalytic properties of WO3. The proposed sensor presented a cost-effective, sensitive, and selective solution, paving the way for non-invasive diabetes monitoring.