Chemiresistive Gas Research Articles

Graphene-based chemiresistive gas sensors.

Gas sensors allow the monitoring of the chemical environment of humans, which is often crucial for their wellbeing or even survival. Miniaturization, reversibility, and selectivity are some of the key challenges for serial use of chemical sensors. This tutorial review describes critical aspects when using nanomaterials as sensing substrates for the application in chemiresistive gas sensors. Graphene has been shown to be a promising candidate, as it allows gas sensors to be operated at room temperature, possibly saving large amounts of energy. In this review, an overview is given on the general mechanisms for gas-sensitive semiconducting materials and the implications of doping and functionalization on the sensing parameters of chemiresistive devices. It shows in detail how different challenges, like sensitivity, response time, reversibility and selectivity have been approached by material development and operation modes. In addition, perspectives from the area of data analysis and intelligent algorithms are presented, which can further enhance these sensors' usability in the field.

Porous materials as effective chemiresistive gas sensors.

Chemiresistive gas sensors (CGSs) have revolutionized the field of gas sensing by providing a low-power, low-cost, and highly sensitive means of detecting harmful gases. This technology works by measuring changes in the conductivity of materials when they interact with a testing gas. While semiconducting metal oxides and two-dimensional (2D) materials have been used for CGSs, they suffer from poor selectivity to specific analytes in the presence of interfering gases and require high operating temperatures, resulting in high signal-to-noise ratios. However, nanoporous materials have emerged as a promising alternative for CGSs due to their high specific surface area, unsaturated metal actives, and density of three-dimensional inter-connected conductive and pendant functional groups. Porous materials have demonstrated excellent response and recovery times, remarkable selectivity, and the ability to detect gases at extremely low concentrations. Herein, our central emphasis is on all aspects of CGSs, with a primary focus on the use of porous materials. Further, we discuss the basic sensing mechanisms and parameters, different types of popular sensing materials, and the critical explanations of various mechanisms involved throughout the sensing process. We have provided examples of remarkable performance demonstrated by sensors using these materials. In addition to this, we compare the performance of porous materials with traditional metal-oxide semiconductors (MOSs) and 2D materials. Finally, we discussed future aspects, shortcomings, and scope for improvement in sensing performance, including the use of metal-organic frameworks (MOFs), covalent-organic frameworks (COFs), and porous organic polymers (POPs), as well as their hybrid counterparts. Overall, CGSs using porous materials have the potential to address a wide range of applications, including monitoring water quality, detecting harmful chemicals, improving surveillance, preventing natural disasters, and improving healthcare.

Atomically dispersed Pt on MOF-derived In2O3 for chemiresistive formaldehyde gas sensing

Single-atom catalysts (SACs) supported on inorganic materials have been confirmed as effective active sites in catalytic reaction. In order to develop gas sensing material with high performance, we reported an atomically dispersed Pt on MOF-derived In2O3 via N doped graphene (NG) sacrificial templating route for the first time. This synthesis strategy, which combines metal-organic frameworks (MOF) precursor and NG template, not only greatly regulates the physicochemical properties of In2O3, but also makes the single-atom Pt be anchored on In2O3. Herein, the effect of Pt and NG was discussed based on various characterization methods. Gas sensing tests revealed that the highly dispersed Pt helps to improve the HCHO sensing performance. The Pt SACs inclusion increases the specific surface area, the contents of oxygen vacancies and adsorbed oxygen species of In2O3, thus increasing the active sites on the surface. These enhancements result in high response (750.4 to 100 ppm), good selectivity, rapid response (2 s to 100 ppm) and low theoretical limit of detection (8.4 ppb) of Pt1-In2O3 based sensor to HCHO. In a word, atomically dispersed Pt loaded MOF-derived In2O3 is an efficient sensing material for selective detection of HCHO.

A General Synthesis of Nanostructured Conductive Metal-Organic Frameworks from Insulating MOF Precursors for Supercapacitors and Chemiresistive Sensors.

Two-dimensional conjugated metal-organic frameworks (2D c-MOFs) are emerging as a unique subclass of layer-stacked crystalline coordination polymers that simultaneously possess porous and conductive properties, and have broad application potential in energy and electronic devices. However, to make the best use of the intrinsic electronic properties and structural features of 2D c-MOFs, the controlled synthesis of hierarchically nanostructured 2D c-MOFs with high crystallinity and customized morphologies is essential, which remains a great challenge. Herein, we present a template strategy to synthesize a library of 2D c-MOFs with controlled morphologies and dimensions via insulating MOFs-to-c-MOFs transformations. The resultant hierarchically nanostructured 2D c-MOFs feature intrinsic electrical conductivity and higher surface areas than the reported bulk-type 2D c-MOFs, which are beneficial for improved access to active sites and enhanced mass transport. As proof-of-concept applications, the hierarchically nanostructured 2D c-MOFs exhibit a superior performance for electrical properties related applications (hollow Cu-BHT nanocubes-based supercapacitor and Cu-HHB nanoflowers-based chemiresistive gas sensor), achieving over 225 % and 250 % improvement in specific capacity and response intensity over the corresponding bulk type c-MOFs, respectively.

Eine allgemeine Strategie zur Synthese von nanostrukturierten leitfähigen MOFs aus isolierenden MOF‐Vorläufern für Superkondensatoren und chemiresistive Sensoren

AbstractZweidimensionale konjugierte metallorganische Gerüstverbindungen (2D c‐MOFs) entwickeln sich zu einer einzigartigen Unterklasse von geschichteten kristallinen Koordinationspolymeren, die gleichzeitig Porosität und elektrische Leitfähigkeit besitzen und ein breites Anwendungspotenzial in Energiespeicherung und elektronischen Geräten haben. Um die intrinsischen elektronischen Eigenschaften und strukturellen Besonderheiten von 2D c‐MOFs optimal nutzen zu können, ist die kontrollierte Synthese von hierarchisch nanostrukturierten 2D c‐MOFs mit hoher Kristallinität und maßgeschneiderten Morphologien unerlässlich, was eine große Herausforderung darstellt. In diesem Artikel stellen wir eine Template‐Strategie zur Synthese einer Bibliothek von 2D c‐MOFs mit kontrollierten Morphologien und Dimensionen über eine Transformation von isolierenden MOFs zu c‐MOFs vor. Die daraus resultierenden hierarchisch nanostrukturierten 2D c‐MOFs weisen höhere intrinsische elektrische Leitfähigkeiten und größere Oberflächen als die literaturbeschriebenen 2D c‐MOFs auf, was für einen verbesserten Zugang zu aktiven Seiten und einen verbesserten Massentransport von Vorteil ist. Als Proof‐of‐Concept‐Anwendungen zeigen die hierarchisch nanostrukturierten 2D c‐MOFs eine überlegene Leistung für Anwendungen welche auf ihren elektrischen Eigenschaften basieren (hohle Cu‐BHT‐Nanowürfel‐basierte Superkondensatoren und Cu‐HHB Nanoblumen‐basierte chemiresistive Gassensoren). Diese erreichen eine Verbesserung der spezifischen Kapazität und der Ansprechintensität von über 225 % bzw. 250 % gegenüber den entsprechenden durch Bulk‐Synthese erhaltenen c‐MOFs.

Metal-decorated 3D tin oxide nanotubes in a monolithic sensor array chip for room-temperature gas identification

Inadequate limit of detection at room temperature and unsatisfactory selectivity remain challenge for wide applications of the chemiresistive gas sensors. Nanostructured gas sensors ensure the desirable activation energy for the gas adsorption and chemical reactions, favorable for room-temperature parts-per-billion (ppb) level gas detection. In this work, we demonstrated a single-chip integrated gas sensor array (4 ×4 pixels) based on kinds of metal (Pt, Pd, Au, Ag) decorated 3D SnO2 nanotubes for ultrasensitive room-temperature gas-sensing. The nanostructured sensor array has a high surface area-to-volume ratio, enabling room temperature sensing with high detection response toward H2 (minimum 5 ppm), formaldehyde (minimum 50 ppb), toluene (minimum 50 ppb) and NO2 (minimum 100 ppb) with the detection accuracy within 5% range, respectively. In addition, the effect of metals decoration on the gas identification features were systematically conducted, and these specific response features can be mainly attributed to metal activation capability toward the gases, which enables demonstrating differentiable response patterns for the target gases identification employing a pattern recognition algorithm. These results demonstrate that the proposed strategy helps to provide an excellent route for the future low-power-consumption smart sensing devices design and fabrication.

Assessment of fish adulteration using SnO2 nanopetal-based gas sensor and machine learning

The work presents the identification of fish adulteration and quality assessment by incorporating a chemiresistive gas sensor and machine learning (ML) techniques. Highly sensitive SnO2 nanopetals were synthesized chemically and integrated with interdigitated electrodes to fabricate a sensor device. The sensor was calibrated with formaldehyde (37 %) with a theoretical detection limit of 75 ppb and further utilized to detect the vapors emitted from fresh and formalin-adulterated fish. An extensive sensing investigation was conducted with freshly caught Rohu fish samples. The sensing behavior was examined for all the samples at different time intervals to estimate the spoilage level. The classification between fresh and adulterated fish samples was obtained with 100 % accuracy by employing ML tools. Moreover, the storage duration and spoilage level of fish samples were quantified using regression models. This work emphasizes the potential of nanomaterials combined with machine learning for the accurate detection of adulteration in food systems.

Metal–organic framework-reduced graphene oxide (Zn-BDC@rGO) composite for selective discrimination among ammonia, carbon monoxide, and sulfur dioxide

The structural diversity and high surface reactivity of the metal–organic frameworks (MOFs) offer an ideal material platform for various applications such as gas storage, gas separation, catalyst, etc. However, their use in chemiresistive gas sensing is limited due to the requirement of optimized gas adsorption properties with electrical conductivity. In the present investigation, we have modulated the electrical properties of zinc benzene dicarboxylate (Zn-BDC) MOF by modifying it with partially reduced graphene oxide (rGO). The Zn-BDC and rGO composite (Zn-BDC@rGO) was synthesized by utilizing a solvothermal method and multiparametrically tested by various techniques such as X-Ray diffraction (XRD), UV–visible spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), thermogravimetric analysis (TGA), and I–V characteristics, for its structural, spectroscopic, morphological, surface area analysis, thermal stability, and electrical characterization, respectively. The synthesized Zn-BDC@rGO composite was deposited via drop casting method on the copper electrodes on a glass substrate (100 µm gap) using the shadow mask technique by the e-beam evaporator, and tested for the detection of ammonia, carbon monoxide, and sulfur dioxide using chemiresistive modality. The principal component analysis (PCA) indicates that the developed sensor selectively discriminates among the NH3, CO, and SO2 gases with low response/recovery time, i.e., 60/120 s at 20 ppm, which is far below the permissible exposure limit (PEL) suggested by The Occupational Safety and Health Administration (OSHA), USA for CO and NH3 and very close to the PEL level of SO2.

Extended-gate structure for carbon-based field effect transistor type formaldehyde gas sensor

Field effect transistor (FET) type gas sensor plays a crucial role in real-time environmental monitoring, medical pre-diagnosis, and industrial control because of its trace hazardous gases detection capability, which can be attributed to the unique amplification of the electrical signal on its gate by FET. Limited by the nano-micro level manufacturing process, the controllable deposition of the tiny sensing gate composed of gas sensing materials and material selection limitations considering semiconductor process compatibility have become bottlenecks in developing FET-type gas sensors. Herein, based on a high-performance FET with semiconducting single-walled carbon nanotubes as the channel, a universal strategy of constructing an extended-gate structure by inkjet printing technology is proposed to realize the detection of trace gases. CuO widely used for HCHO detection is applied to this strategy, and the as-prepared EG-FET sensor has a limit of detection of 20 ppb for HCHO, good repeatability, long-term stability, and selectivity, which greatly improves the ability of conventional chemiresistive gas sensor to detect HCHO. The development of the EG structure makes the controlled deposition of gas sensing materials more accessible, and the introduction of inkjet printing expands the choices of sensing materials. In particular, it solves the issue of poor reproducibility in the fabrication of gas sensors from gas sensing materials and provides a feasible scheme for the reported excellent gas sensing materials from laboratory to application. We expect this work can provide a meaningful theoretical and experimental basis for the realization of high-performance trace gas sensors with the potential for on-chip integration.

In-situ/operando characterization of FeOx-based chemiresistive sensor of acetone vapours by X-ray absorption spectroscopy

Metal oxide thin films are archetypal active elements employed in chemiresistive gas sensors. Most existing metal oxide-based sensors operate at elevated temperatures; however, the sensing mechanism has generally been deduced considering the room-temperature properties of metal oxide compounds. We report an in-operando X-ray absorption spectroscopy study on a chemiresistive sensor of acetone vapours; namely, the chemical structure of iron-oxide nanoparticles (NPs) exposed to trace concentrations of acetone vapours under varying temperature conditions was examined. Our results show that the iron-oxide NPs, identified as maghemite/magnetite (γ-Fe2O3/Fe3O4) compound, partially reduced with temperature. Likewise, the iron oxide NPs were partially reduced upon exposure to trace concentrations of acetone vapour (at constant temperature). The latter observation suggests that acetone molecules are chemically adsorbed on iron oxide. The chemical changes are discussed in terms of the conductive response of a consubstantial chemiresistive sensor. Acetone chemisorption requires a revision of the commonly accepted sensing mechanism based on the physical adsorption of acetone molecules.

Fabrication of ZnO-SnO2 heterojunction inverse opal photonic balls for chemiresistive acetone sensing

The development of metal oxide semiconductor-based chemiresistive gas sensors with ultra-fast response/recovery for toxic and flammable gases is of great importance, but still challenging. Here, ZnO-SnO2 heterojunction three-dimensional (3D) inverse opal photonic crystal balls (IOPBs) were fabricated based on rapid and liquid waste-free spray drying. The spherical three-dimensional (3D) ordered macroporous skeleton can provide more active sites and faster gas diffusion channels. Furthermore, the n-n heterojunction established by ZnO and SnO2 is favorable for electron transport. The response (Ra/Rg) of IOPBs to 50 ppm acetone reaches 40.3 at an optimal operating temperature of 260 °C when the Zn/Sn atomic ratio is 1:4, which is 5 times higher than that of the pure SnO2 sensor. Response/recovery time also reduces from 23/47 s for pure SnO2 to 6/10 s. In addition, the IOPBs gas sensors also exhibit good selectivity and excellent long-term stability. This work provides a straightforward and versatile synthetic route for the preparation of 3D IOPBs to explore novel gas sensors with ultra-fast response speed.

Recent Advances of Graphene Quantum Dots in Chemiresistive Gas Sensors.

Graphene quantum dots (GQDs), as 0D graphene nanomaterials, have aroused increasing interest in chemiresistive gas sensors owing to their remarkable physicochemical properties and tunable electronic structures. Research on GQDs has been booming over the past decades, and a number of excellent review articles have been provided on various other sensing principles of GQDs, such as fluorescence-based ion-sensing, bio-sensing, bio-imaging, and electrochemical, photoelectrochemical, and electrochemiluminescence sensing, and therapeutic, energy and catalysis applications. However, so far, there is no single review article on the application of GQDs in the field of chemiresistive gas sensing. This is our primary inspiration for writing this review, with a focus on the chemiresistive gas sensors reported using GQD-based composites. In this review, the various synthesized strategies of GQDs and its composites, gas sensing enhancement mechanisms, and the resulting sensing characteristics are presented. Finally, the current challenges and future prospects of GQDs in the abovementioned application filed have been discussed for the more rational design of advanced GQDs-based gas-sensing materials and innovative gas sensors with novel functionalities.

A chemiresistive room temperature ammonia gas sensor based on self-assembled PPy/Zntpp

There is an increasing demand for monitoring ammonia in livestock farming, which can prevent livestock products from being contaminated by bacteria and viruses. As a prospective material for resistive sensors, polypyrrole (PPy) still suffers from low sensitivity and poor selectivity. Herein, zinc-tetra(p-sulfonylphenyl) porphyrin (Zntpp) particles are anchored on the PPy network by a one-step mild electrodeposition route to form a resistive sensor with the wrinkle-like nanostructure. The optimal PPy/Zntpp (Pzt) sensor demonstrates an outstanding response value of 104.3 % toward ammonia with a response/recovery time of 42/223 s, compared with that of PPy (7.2 % in response and 47/230 s). The durability and stabilities have been explored, and the limit of detection for Pzt is calculated to be ∼8.63 ppm, which enables trace ammonia in livestock farming. Additionally, the sensing mechanism can be attributed to the p-n heterojunction. Furthermore, a wireless sensor device that consists of a Pzt sensory unit, a microcomputer, and a Bluetooth module is assembled, and the concentration information can be read precisely in real-time by a smartphone, indicating the great application prospects in the field of livestock farming.

Ag decorated CuGaO2 nanosheets for enhanced ethylene glycol detection

Metal oxide semiconductors stand at an essential frontier of chemiresistive substance for gas sensor assembly to detect the volatile organic compounds, especially in case of the trace amount related to human health. In this work, we present a new gas sensor based on hydrothermally synthesized CuGaO2 nanosheets with Ag decoration, which performs an enhanced selectivity, sensitivity, and response/recovery speed towards ethylene glycol. Based on the structural characterization and systematic gas detection results, the gas sensing mechanism is elucidated by the first principles calculations and energy band theoretic analysis, in which the extraordinary gaseous adsorption and charge transfer onto the solid surface is responsible for the high susceptibility of Ag decorated CuGaO2 to ethylene glycol. Meanwhile, Ag hybridization is further confirmed to provide the additional approach to boost the efficiency of electron transfer. It is an innovative perspective to study the chemiresistive gas sensing by comparing the preference of charge transfer from the adsorbed organic gas molecule towards the hybridized solid surface, which presents a new route to design the material system of advanced sensing devices for the specific applications.

Developing a ternary conductive hydrogel of polyacrylamide, polyaniline, and carbon nanotube: A potential chemiresistive gas sensor

Over the past few years, conductive hydrogels have received increasing attention for numerous electronic applications because of the concurrent provision of electrical conductivity, flexibility, and conformability. In the present study, a polyaniline-based conductive hydrogel was synthesized. Carbon nanotubes (CNTs) were associated with the hydrogel to impart higher electrical conductivity to the hydrogel, and ternary composites of polyacrylamide (PAM), polyaniline (PANI), and CNT were developed. To fulfill this, at first, CNT surface was decorated with carboxyl functionalities, and the carboxyl decorated CNT was included into the composition in two manners: firstly, CNTs were included during acrylamide polymerization, whereas in the second manner, CNTs were incorporated during aniline polymerization. The composite hydrogels' chemical, swelling, morphological, and electrical properties were evaluated. The experimental results corroborated that in the latter case, abundant intermolecular interactions were developed between the PANI chains and the CNT surface. Moreover, the swelling value was increased by 9% comapred to the former case. In the former case, a porous microstructure and in the latter case a fibrous microstructure was dominated. And more importantly, the electrical conductivity of the hydrogel in the latter case was 104 folds higher than that in the former case. The ternary composition prepared with the latter manner was employed for sensing the ammonia gas, and the analyses unveiled that the hydrogel represents an appropriate response in the range of 10.43%–16.87% to various concentrations of the target gas and has the potential to be a thriving chemiresistive gas sensor.

Temperature-driven n- to p-type transition of a chemiresistive NiO/CdS-CdO NO2 gas sensor

A new NiO/CdS-CdO composite-based chemiresistive gas sensor for NO2 detection exhibits temperature-driven adsorption switching. In-situ CdS nanoparticle growth on Ni-based metal-organic framework (MOF) spheres produced Ni-MOF/CdS, and then calcinating the Ni-MOF/CdS in air yielded NiO/CdS-CdO composite. The composite's NO2 sensing characteristics were examined at 25–350 °C, demonstrating that the NiO/CdS-CdO composite switches from n- to p-type above 200 °C with strong NO2 sensitivity and selectivity. Adsorption switching allows the NiO/CdS-CdO composite to serve as a dual-mode sensor, where NiO and CdS-CdO dominate at higher temperatures (>200 °C) and lower temperatures (≤200 °C) with realistic detection ability, respectively. This switching is mainly caused by variations in charge carrier concentration and NO2 adsorption/desorption behavior on the composite surface. At 150 °C, NiO/CdS-CdO sensors have a low detection limit of 100 ppb, high response (Rg/Ra, ∼215), quick response time (∼47 s), and recovery time (∼66 s) at 100 ppm. FTIR analysis, estimation of activation energies, and a qualitative comparison of n- to p-type transition with a typical full-wave rectification process explain the adsorption switching phenomenon. Adsorption switching in NiO/CdS-CdO-based gas sensors with great repeatability, stability, and fast response may be a promising route for high-performance gas sensing applications.

A Polymer‐Based Chemiresistive Gas Sensor for Selective Detection of Ammonia Gas

AbstractBreath analysis is a non‐invasive tool used in medical diagnosis. However, the current generation of breath analyzers is expensive, time‐consuming, and requires sample gas separation. In this work, a simple, yet effective, low‐cost ammonia gas sensor based on poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid) is presented for non‐invasive medical diagnosis. The designed sensor has a broad detection range to ammonia gas up to 1000 ppm with a limit of detection of 30 ppb. This is a robust sensor, which functions at high relative humidity (RH) (>90%) and exhibits consistent electrical responses under different test conditions. The result of a blind test validates the sensor's selective response to ammonia in the presence of other gases such as carbon dioxide. Furthermore, it is viable to integrate this sensor into a mask for real‐time ammonia gas detection accurately. Overall, this study demonstrates the feasibility of developing a simple, non‐invasive, and cost‐effective sensor for real‐time monitoring of ammonia gas with high potential in applications such as medical diagnostics, food safety, and environmental conditions.

3D hybrid materials based on zinc and cobalt phthalocyanine derivatives bearing terminal ethynyl substituents as active layers for chemiresistive gas sensors

Porous 3D hybrid materials (SWCNT/CoPc and SWCNT/ZnPc) were prepared by the reaction between single walled carbon nanotubes (SWCNT) functionalized with azido groups and ZnPc or CoPc phthalocyanines containing 16 terminal ethynyl groups and characterized by various physical methods. It was shown by thermogravimetric analysis (TGA) that the number of CoPc molecules attached on the SWCNT surface was one CoPc molecule per 115 carbon atoms, which is larger than in the case of the SWCNT/ZnPc (one ZnPc molecule per 312 carbon atoms). The prepared hybrids were studied as active layers of chemiresistive sensors for the detecting gaseous H2S at low concentrations (0.1–50 ppm). It was found that the sensor response of SWCNT/CoPc was about 4 times higher than in the case of SWCNT/ZnPc, which correlated well with the larger number of CoPc molecules on the SWCNT surface. The prepared hybrids are promising materials for the creation of fully reversible sensors for the detection of H2S at room temperature. The calculated LOD (3σ/m) of H2S was 18 and 65 ppb for SWCNT/CoPc and SWCNT/ZnPc, respectively.

Flash-Thermal Shock Synthesis of Single Atoms in Ambient Air.

Single-atom catalysts feature interesting catalytic activity toward applications that rely on surface reactions such as electrochemical energy storage, catalysis, and gas sensors. However, conventional synthetic approaches for such catalysts require extended periods of high-temperature annealing in vacuum systems, limiting their throughput and increasing their production cost. Herein, we report an ultrafast flash-thermal shock (FTS)-induced annealing technique (temperature > 2850 °C, <10 ms duration, and ramping/cooling rates of ∼105 K/s) that operates in an ambient-air environment to prepare single-atom-stabilized N-doped graphene. Melamine is utilized as an N-doping source to provide thermodynamically favorable metal-nitrogen bonding sites, resulting in a uniform and high-density atomic distribution of single metal atoms. To demonstrate the practical utility of the single-atom-stabilized N-doped graphene produced by the FTS method, we showcased their chemiresistive gas sensing capabilities and electrocatalytic activities. Overall, the air-ambient, ultrafast, and versatile (e.g., Co, Ni, Pt, and Co-Ni dual metal) FTS method provides a general route for high-throughput, large area, and vacuum-free manufacturing of single-atom catalysts.

WO3 nanoparticles supported by Nb2CTx MXene for superior acetone detection under high humidity

Chemiresistive gas sensors have emerged as a promising generation of detection systems for identifying trace biomarker molecules in exhaled breath, potentially replacing conventional devices for early-stage disease diagnosis. However, their potential is currently limited by the absence of sensing materials that exhibit both humidity resistance and ultrasensitivity. In this study, we investigate the potential of WO3 nanoparticles (NPs) supported by Nb2CTx MXene (WO3/Nb2CTx) as a highly efficient material for acetone sensing. Our results demonstrate that the synergistic interplay between WO3 NPs and Nb2CTx MXene support generates an intriguing interface with chemical/electronic coupling, thereby further enhancing the gas sensing performance. The WO3/Nb2CTx sensor exhibits exceptional sensing performance for acetone, with ultrasensitivity (Ra/Rg = 2.4 at 50 ppb) and an ultrafast response time (8 s), surpassing that of WO3 alone, while maintaining excellent stability. Moreover, the sensor exhibits outstanding response intensity, rapid response time (9 s), superior selectivity, and remarkable reversibility at a relative humidity of approximately 90 %. Additionally, we evaluate the gas-sensing properties of the sensor towards simulated exhaled breath of diabetic patients. In conclusion, our study presents a novel approach that integrates NPs and MXenes, which holds promise for the development of gas sensors with resistance to humidity interference.