Excellent Detection Capability Research Articles

Flexible assembly of the PEDOT: PSS/ exfoliated β-Ga2O3 microwire hybrid heterojunction for high-performance self-powered solar-blind photodetector.

Motivated by the goals of fabricating highly reliable, high performance, and cost-efficient self-powered photodetector (PD) for numerous scientific research and civil fields, an organic-inorganic hybrid solar-blind ultraviolet (UV) PD based on PEDOT: PSS/exfoliated β-Ga2O3 microwire heterojunction was fabricated by a flexible and cost-effective assembly method. Benefiting from the heterojunction constructed by the highly crystalline β-Ga2O3 and the excellent hole transport layer PEDOT: PSS, the device presents a high responsivity of 39.8 mA/W at 250 nm and a sharp cut-off edge at 280 nm without any power supply. Additionally, the ultra-high normalized photo-to-dark current ratio (> 104 mW-1cm2) under reverse bias and the superior detectivity of 2.4×1012 Jones at zero bias demonstrate the excellent detection capabilities. Furthermore, the hybrid PD exhibits a rapid rise time (several milliseconds) and high rejection ratio (R250/R365: 5.8 × 103), which further highlights its good spectral selectivity for solar-blind UV. The prominent performance is mainly ascribed to the efficient separation of the photogenerated carriers by the large built-in electric field of the advanced heterojunction. This flexible assembly strategy for solar-blind UV PD combines the advantages of high efficiency, low cost and high performance, providing more potential for PD investigation and application in the future.

Mixed Co‐Mn Spinel Oxides Based Electrocatalysts for Amperometric Determination of Hydrogen Peroxide

AbstractHerein, we present an efficient non‐enzymatic electrochemical sensor for H2O2 detection based on the catalytic‐reduction of H2O2 on ZnMn0.5Co1.5O4. The ZnMn0.5Co1.5O4 derived from ZnCo2O4 by the partial substitution of Co with Mn was synthesized via sol‐gel combustion method. The catalytic performance of ZnMn0.5Co1.5O4 for the reduction of H2O2 is better than that of ZnCo2O4, attributing to the synergetic effects of electronic structure, lattice distortion, and multivalent state of Mn. Specifically, as‐fabricated ZnMn0.5Co1.5O4‐based electrochemical sensor shows an excellent quantitative detection capability toward H2O2 in a wide range of 5 to 7585 μM, with a theoretical detection limit of 0.12 μM (3S/N). Moreover, the excellent reproducibility and selectivity for H2O2 sensing was also verified. The excellent recoveries from 94.4 to 103.2 % were obtained for H2O2‐spiked orange juice and beer. More importantly, the sensor exhibits desirable performance in the real‐time monitoring of H2O2 released from living human colon cancer cell (HCT116 cells). The results indicate that the as‐presented sensor is a promising candidate for the H2O2 determination in food safety and clinical diagnose.

Urban rail transit obstacle detection based on Improved R-CNN

Excellent active obstacle detection capability is critical to operate fully automatic trains safely and reliably. There are some problems exist in the traditional sensor-based obstacle detection approaches, such as low detection accuracy, sluggish detection speed and a limited number of obstacle types. In this work, a fast and accurate object detector termed improved R-CNN is proposed by introducing new up-sampling parallel structure and context extraction module (CEM) into the architecture of R-CNN. Furthermore, transfer learning is applied to inherit the COCO dataset's pre-training weight. The network is trained on track lines and test lines with nine types of obstacles. The data is evaluated and statistically cleansed, and the fine-tuning anchor improves the network's flexibility within the dataset. With the input size of 1330 px × 800 px, the test results show that the improved R-CNN model achieves an accuracy of 90.6% and a detection speed of 11 FPS. In comparison to other state-of-the-art detectors, the model has great performance in obstacle identification of rail track and achieves a good balance between detection speed and accuracy.

A Novel Integrated APCI and MPT Ionization Technique as Online Sensor for Trace Pesticides Detection.

The misuse of pesticides poses a tremendous threat to human health. Excessive pesticide residues have been shown to cause many diseases. Many sensor detection methods have been developed, but most of them suffer from problems such as slow detection speed or narrow detection range. So, the development of rapid, direct and sensitive means of detecting trace amounts of pesticide residues is always necessary. A novel online sensor technique was developed for direct analysis of pesticides in complex matrices with no sample pretreatment. The portable sensor ion source consists of an MPT (microwave plasma torch) with desolventizing capability and an APCI (atmosphere pressure chemical ionization), which provides abundant precursor ions and a strong electric field. The performance which improves the ionization efficiency and suppresses the background signal was verified by using pesticide standard solution and pesticide pear juice solution measurements with an Orbitrap mass spectrometer. The limit of detection (LOD) and the limit of quantization (LOQ) of the method were measured by pear juice solutions that were obtained in the ranges of 0.034–0.79 μg/L and 0.14–1 μg/L. Quantitative curves were obtained ranging from 0.5 to 100 μg/L that showed excellent semi-quantitative ability with correlation coefficients of 0.985–0.997. The recoveries (%) of atrazine, imidacloprid, dimethoate, profenofos, chlorpyrifos, and dichlorvos were 96.6%, 112.7%, 88.1%, 85.5%, 89.2%, and 101.9% with the RSDs ranging from 5.89–14.87%, respectively. The results show that the method has excellent sensitivity and quantification capability for rapid and direct detection of trace pesticide.

An Endpoint Detection System for Ion Beam Etching Using Optical Emission Spectroscopy

An ion beam etching system with etching endpoint detection (EPD) capability based on optical emission spectroscopy (OES) was conceived, built, and tested. An expansion chamber was added on the right side of the etching chamber to fix the optical detector for in-situ detecting. In this system, the optical detector was mounted on a seven-shaped bracket, which was fixed by two straight guides, thus the position of the optical detector could be adjusted arbitrarily to collect the emission spectrum generated by the sample during the etching process. The signal was transmitted by optical fiber to the computer for processing, and the etching endpoint could be detected after analyzing the data. Firstly, we used simple substances (Al, Cr, Si, and Mg) to analyze the feasibility of the system and determine the best position of the optical detector. In addition, we also tested the detection limit of the system. Finally, a complex multilayer film sample with different materials was tested, and the results showed that the system could clearly detect the characteristic emission lines of different layers and had a good real-time performance and excellent endpoint detection capabilities.

Detection of volatile organic compounds from human prostate cancer cell using canine olfaction

Prostate cancer (PCa) is one of the most prevalent cancers of men worldwide. Currently, evaluating serum prostate-specific antigen, combined with digital rectal examination, is used as the diagnostic approach for early detection of PCa, but it has low sensitivity and difficulty in discriminating from non-malignant conditions such as prostatitis and benign prostate hyperplasia. As an alternative, a number of previous studies have reported detection of volatile organic compounds (VOCs) from biofluids of patients with PCa. However, biofluids have several drawbacks including limited availability and lack of standardization. Therefore, as a proof-of-concept study, VOCs from extracellular medium of PCa cell line were used in present study. The detection of the VOCs was performed by canine olfaction as dogs have a superior olfactory system and the purpose of this study was to evaluate whether canine olfaction can be used to detect VOCs of cancer cell line. Two dogs were trained to discriminate VOCs of the PCa cell line (PC3) from those of control groups. Tests were performed by evaluating the ability to detect VOCs of PC3 and those of PCa cell line (DU145) and bladder cancer cell line (EJ cell) for which the dogs were not trained. Sensitivity, specificity, and area under the curve (AUC) by receiver operating characteristic curve analysis were evaluated. In detecting VOCs of PC3, the AUC values of the 2 dogs were 0.956 and 0.976, which represented excellent detection capability. The AUC values of the DU145 were 0.892 and 0.840 and the AUC values of the EJ cell were 0.921 and 0.965. The dogs not only showed good detection ability against DU145 which originated from the same organ as PC3, but also exhibited excellent detection ability against EJ cell which originated from a different organ. In conclusion, VOCs of PCa cell line can be used to train scent-detection dogs. Further study is needed to define specific factors among VOCs that create differences between cells and to identify whether VOCs of PCa cell line can replace that of real PCa.

Ultralow detection limit MEMS hydrogen sensor based on SnO2 with oxygen vacancies

Controllable and efficient construction of oxygen vacancies on the surface of metal oxide semiconductors (MOSs) is essential for their application in the gas sensor. Herein, a general H2 reduction method is developed to synthesize SnO2 with oxygen vacancies defect (SnO2-D) by annealing the SnO2 in a H2 atmosphere at different temperature (300 °C, 400 °C and 500 °C), and then named SnO2-D3, SnO2-D4 and SnO2-D5, respectively. It was found that although the determined specific surface areas for pristine SnO2, SnO2-D3, SnO2-D4 and SnO2-D5 are 103.749 m2g−1, 63.316 m2g−1, 47.652 m2g−1 and 15.541 m2g−1, respectively, the gas sensitivity test results indicate that the SnO2-D4 Micro-Electro-Mechanical System (MEMS) sensor shows improved response and excellent low-concentration detection capability (down to 0.1 ppm) to H2 compared with that fabricated with pristine SnO2, SnO2-D3 and SnO2-D5. The abnormal relationship between specific surface area and gas sensing performance is attributed to the more oxygen vacancies of SnO2-D4 surface. In addition, ZnO (ZnO-D) and In2O3 (In2O3-D) with oxygen vacancy defects based on the H2 reduction method show better gas sensitivity than ZnO and In2O3 sensors, which further proves that oxygen vacancy defects can effectively improve the gas-sensing performance of MOSs.

Electrochemical determination of paraquat using a glassy carbon electrode decorated with pillararene-coated nitrogen-doped carbon dots

An electrochemical sensor (carboxylatopillar[5]arene-coated nitrogen-doped carbon dots, namely CCDs) based on carboxylatopillar[5]arene (CP[5]) functionalized nitrogen-doped carbon dots (N-CDs) has been developed in a facile and economic manner. To improve the performance of this electrochemical sensor in pesticide detection, the optimal solution pH (pH 7) and loading amount of CCDs on the electrode (0.50 mg/mL) have been determined. By virtue of the good conductivity of N-CDs and the molecular recognition property of CP[5], CCDs modified glassy carbon electrode, namely CCDs/GCE, shows excellent anti-interference capability, selectivity, stability, and reproducibility in the sensitive detection of paraquat. The peak currents are proportional to the paraquat concentration (from 0.1 µmol/L to 10 µmol/L) with a detection limit of 6.4 nmol/L (S/N = 3), indicating a great potential in pesticide detection. In comparison with the electrochemical sensors that require expensive metal nanoparticles and complex preparation processes, CCDs/GCE exhibits excellent detection capability of paraquat with lower cost and simpler preparation processes.

‘Quick CuAAC’ Chemistry for Hg(II) and Mn(II) ion sensing via 9H-carbazole derivatives

The synthesis of 1,2,3-triazole merged 9H–carbazole derivative is being reported with excellent yield but drastic reduction in the reaction time. The 1,2,3-triazole linker has been synthesized under thermal conditions within 20 min and yield of more than 90%, using Cu(I) as catalyst. Using UV–Vis spectral technique, the alkyne product displayed excellent detection capability towards Hg(II) and Mn(II) ions in methanol with the detection limit as low as 20 µM and 10 µM, respectively, whereas the triazolyl product can efficiently sense Cu(II) ions.

Relocating microseismicity from downhole monitoring of the Decatur CCS site using a modified double-difference algorithm

SUMMARYThe injection of CO2 at the Decatur carbon capture and storage site has generated significant microseismic activity, which occurs in distinct spatial clusters up to approximately 2.2 km from the primary injection well. Accurate and precise event locations are vital for the characterization of the microseismicity to help understand the reservoir response to the CO2 injection, whilst enabling the identification of minor faults and fractures below the resolution of conventional active seismic imaging. However, microseismic monitoring of fluid injection sites, such as Decatur, is often performed using a network of borehole sensors often from a single well. While these downhole sensors have excellent detection capabilities, their poor azimuthal coverage limits the ability to precisely determine event locations. We have developed a modified double-difference relocation algorithm suitable for both 1-D and 3-D velocity models, and which incorporates differential back azimuth observations to allow the benefits of the original double-difference algorithm to be applicable to a downhole microseismic monitoring setting. Applying the modified double-difference algorithm to the microseismicity at Decatur, we have successfully relocated 4293 events. The relocation included over 59 million observations for 757 285 event pairs, split across seven geographic regions. Despite the majority of observations being recorded in only two boreholes, with an almost identical azimuthal coverage, the results have shown to be reliable with significantly reduced residuals and low uncertainties associated with the final locations. We have analysed the residuals in terms of their association with each geographic region, data type, station and individual events, to fully appreciate their influence in the inversion and the fit of the data to the final set of event locations. For each region, the relocated seismicity has become less diffuse with improved clustering, and with newly visible linear features often orientated in a NE–SW direction. These results show the potential improvements that can be made to microseismic event locations recorded by a borehole network with a limited and variable azimuthal distribution.

NCL-based mitochondrial-targeting fluorescent probe for the detection of Glutathione in living cells

Glutathione (GSH) plays a critical role in maintaining cellular redox homeostasis in biological system. Mitochondrion is a pivotal organelle for cellular aerobic respiration and its disorder is associated with impaired redox balance, leading to cell death. In this work, we designed and synthesized a non-invasive “off-on” mitochondrial-targeting fluorescent probe QZ for the detection of GSH in living cells. Based on the mechanism of native chemical ligation (NCL) and fluorescence resonance energy transfer (FRET), a rhodamine B derivative, QZ was prepared, by choosing aromatic thioester bond as the selective reaction site. QZ exhibited excellent detection capability for GSH over Cys and Hcy. Upon addition of GSH to QZ solution, a remarkably enhanced fluorescence was observed with a limit of detection of 2.98 µmol/L. Furthermore, QZ was found to possess the specific mitochondrial localization ability in cell imaging experiments. Moreover, with exogenous and endogenous stimulations, QZ could image GSH in living cells.

A smart TP-FRET-based ratiometric fluorescent sensor for bisulfite/formaldehyde detection and its imaging application

Bisulfite (HSO3−) and formaldehyde (FA) are hazardous environmental pollutants that pose serious risks to human health. Herein, we report for the first time a novel TP-FRET-based TP-ratiometric reversible fluorescence sensor NPXH, which is based on combining TP naphthalimide fluorophore with a deep red-emitting xanthene fluorophore via a nonconjugated linker, for reversible detection of bisulfite/formaldehyde. In presence of HSO3−, NPXH shows a significant ratio enhancement (∼6-fold) in I535/I630, ultra-fast response (less than 8 s) and super low detection limit (7.48 nM). In addition, the fluorescence signal of NPXH is easily and rapidly recovered by FA within 1 min. More impressively, NPXH has shown excellent detection capability in food and water samples and has been successfully applied to HSO3−/FA detection in liver tissue, zebrafish and mice.

PH-Amplified CRET Nanoparticles for In Vivo Imaging of Tumor Metastatic Lymph Nodes.

Noninvasive imaging strategies have been extensively investigated for in vivo mapping of sentinel lymph nodes (SLNs). However, the current imaging strategies fail to accurately assess tumor metastatic status in SLNs with high sensitivity. Here we report pH-amplified self-illuminating near-infrared nanoparticles, which integrate chemiluminescence resonance energy transfer (CRET) and signal amplification strategy, enabling accurate identification of metastatic SLNs. After draining into lymph nodes, the nanoparticles were phagocytosed and dissociated in acidic phagosomes of inflammatory macrophages to emit near-infrared luminescent light. Using these nanoparticles, we successfully differentiated tumor metastatic lymph nodes from benign ones. These nanoparticles also exhibited excellent imaging capability for early detection of metastatic SLNs in diverse animal tumor models with small tumor volume (100-200 mm3 ).

PH‐Amplified CRET Nanoparticles for In Vivo Imaging of Tumor Metastatic Lymph Nodes

AbstractNoninvasive imaging strategies have been extensively investigated for in vivo mapping of sentinel lymph nodes (SLNs). However, the current imaging strategies fail to accurately assess tumor metastatic status in SLNs with high sensitivity. Here we report pH‐amplified self‐illuminating near‐infrared nanoparticles, which integrate chemiluminescence resonance energy transfer (CRET) and signal amplification strategy, enabling accurate identification of metastatic SLNs. After draining into lymph nodes, the nanoparticles were phagocytosed and dissociated in acidic phagosomes of inflammatory macrophages to emit near‐infrared luminescent light. Using these nanoparticles, we successfully differentiated tumor metastatic lymph nodes from benign ones. These nanoparticles also exhibited excellent imaging capability for early detection of metastatic SLNs in diverse animal tumor models with small tumor volume (100–200 mm3).

A new organic-inorganic MgZnO/Au/PEDOT:PSS hybrid heterojunction photodetector fabrication

AbatractThis research reports oxygen zinc magnesium (MgZnO)/gold (Au) photodetectors (PD) and organic-inorganic semiconductors MgZnO/Au/poly(3,4-ethylenedioxythio-phene): poly(4-styrenesulfonate) (PEDOT:PSS) PD research. At room temperature, spin-coating and radio frequency (RF) magnetron sputtering were used to deposit PEDOT:PSS layer and MgZnO thin film on the substrate, respectively. The properties of the heterojunction formed on the MgZnO/PEDOT:PSS inorganic/organic contact interface were studied. In order to manufacture ultraviolet (UV) heterojunction PDs, PEDOT:PSS is used as the hole transport layer (HTL), and MgZnO is used as the electron transport layer (ETL). This heterojunction shows excellent ultraviolet light detection capability. Under 40 V bias, the responsivity of MgZnO/Au PD and MgZnO/Au/PEDOT:PSS heterojunction PD are 0.0473 A W−1 and 0.134 A W−1 under ultraviolet irradiation, respectively. The device shows good Schottky contact between metal semiconductor junctions. The excellent UV detector performance is due to the strong UV absorption of PEDOT: PSS.

Study on Specific Apis cerana Honeybee Queen Pheromone Biosensor Based on Pheromone-Binding Protein ASP1

Biosensor is a detection device composed of a biologically active unit and a signal converter. In a eusocial honeybee colony, worker bees have also evolved a sophisticated olfactory system to specifically sense the queen pheromone components. So far, it is not clear whether it is possible to design a biosensor to detect the queen pheromone in vitro by using worker bees' olfactory system. In this study, a specific pheromone biosensor was successfully constructed by immobilizing the recombinant honeybees' pheromone binding protein 1 (PBP1/ASP1) on the forked finger gold electrode using nitrocellulose membrane. The results showed that the maximum resistance charge transfer (Rct) changes of two queen pheromone components [methyl p-hydroxy-benzoate (HOB) and vanillyl alcohol (HVA)] reached 60%, which were significantly higher than those of a bee larval pheromone component (ethyl oleate), and a floral volatile ($\beta $ -ionone). The linear detection of HOB and HVA ranged from 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-7</sup> to 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-4</sup> mol/L, and the theoretical detection limit reached 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-8</sup> mol/L, indicating the wide detection linear range and excellent detection capability of this biosensor. These results indicated that the biosensor was highly sensitive and specific to the queen pheromone components. It is beneficial to protect and maintain the sustainability of honeybee resources in the future.

Geometrical reconstruction of fluorescence events observed by the LHAASO experiment * *Supported by National Natural Science Foundation of China (11903005, 11563004, 11475190)

The LHAASO-WFCTA experiment, which aims to observe cosmic rays in the sub-EeV range using the fluorescence technique, uses a new generation of high-performance telescopes. To ensure that the experiment has excellent detection capability associated with the measurement of the energy spectrum, the primary composition of cosmic rays, and so on, an accurate geometrical reconstruction of air-shower events is fundamental. This paper describes the development and testing of geometrical reconstruction for stereo viewed events using the WFCTA (Wide Field of view Cherenkov/Fluorescence Telescope Array) detectors. Two approaches, which take full advantage of the WFCTA detectors, are investigated. One is the stereo-angular method, which uses the pointing of triggered SiPMs in the shower trajectory, and the other is the stereo-timing method, which uses the triggering time of the fired SiPMs. The results show that both methods have good geometrical resolution; the resolution of the stereo-timing method is slightly better than the stereo-angular method because the resolution of the latter is slightly limited by the shower track length.

Sensitive fluorescence and visual detection of organophosphorus pesticides with a Ru(bpy)32+-ZIF-90-MnO2 sensing platform.

Fluorescence sensing organophosphorus pesticides (OPs) is of great importance for both food safety and global environment; however, the reported fluorescent probes are usually directly exposed to the external environment, resulting in premature leakage or photobleaching and thus limiting their photostability and assay sensitivity. In this work, a fluorescent sensing platform consisting of a novel luminescent metal-organic framework (Ru(bpy)32+-ZIF-90) and manganese dioxide nanosheets (MnO2 NSs) was prepared for sensing OPs. Due to the protection and improvement in the fluorescence of Ru(bpy)32+ by ZIF-90, the Ru(bpy)32+-ZIF-90 probe displayed remarkable photostability and high stability in water. By virtue of the high stability of Ru(bpy)32+-ZIF-90, as well as the outstanding fluorescence quenching and notable recognition ability of the MnO2 NSs, this sensing platform provided excellent detection capability for parathion-methyl, with a wide concentration range of 0.050-60 ng mL-1 and a low detection limit of 0.037 ng mL-1. Additionally, the system exhibited a visual color change with the concentration of the OPs under sunlight. Moreover, satisfactory recoveries ranging from 93.3% to 103.6% were obtained for the real samples. The results indicated that the Ru(bpy)32+-ZIF-90-MnO2-based OP sensing platform is promising for applications in food safety and environmental monitoring.

Detection and Diagnosis of Xylella fastidiosa by Specific Monoclonal Antibodies

Monoclonal antibodies (MAb) specific to Xylella fastidiosa were obtained through hybridoma technology using heat-treated somatic O antigens from LMG 17159strain. Ten stable hybrydoma clones secreting MAb were selected and their isotype was determined. The MAbs 2G1/PPD, IgG1 showed specificity for X. fastidiosa, detecting all the analyzed strains representing different subspecies, STs and hosts. Polyclonal antibodies (PAb) against X. fastidiosa were also produced and antiserum 17159-O/IVIA was selected for the highest titre and its excellent detection capability. MAb 2G1/PPD was tested against strain IVIA 5235 in PBS and in spiked raw extract samples from almond, olive, citrus, and other hosts and its sensitivity by DAS-ELISA was 104 CFU mL−1. The MAb also reacted with high affinity and avidity against X. fastidiosa by DASI-ELISA and Tissue print-ELISA. The diagnostic parameters of DAS-ELISA based on MAb were calculated and compared with the gold standard real-time PCR. The diagnostic specificity of MAb2G1/PPD was 100%, the diagnostic sensitivity was 88.5% compared to Harper’s real-time PCR and 89.9% compared to Francis’ real-time PCR. The agreement between the techniques was almost perfect according to the estimated Cohen’s kappa-index, even in symptomless almond trees. The developed immunological techniques represent sustainable and low-cost analysis tools, based on specific, homogeneous, and well-characterized MAbs, which can be obtained in unlimited quantities in a reproducible way and constitute a guarantee for the standardization of commercial kits. They are a valuable option within a polyphasic strategy for the detection of X. fastidiosa.

High-Sensitive MEMS Hydrogen Sulfide Sensor made from PdRh Bimetal Hollow Nanoframe Decorated Metal Oxides and Sensitization Mechanism Study.

Here we report the fabrication of a high performance metal oxide semiconductor (MOS) sensor for the detection of hydrogen sulfide (H2S) using PdRh bimetal hollow nanocube (HC) with Rh-rich hollow frame and Pd-rich core frame as sensitizing materials. PdRh bimetal HC with the edge-length about 10 nm was prepared by chemical etching PdRh bimetal solid nanocube (SC) in HNO3 aqueous solution. The results of gas-sensing tests indicate that the response value order of the MEMS gas sensors based on MOSs (including ZnO, MoO3 and SnO2) is as follows: RPdRhHC/MOS > RPdRhSC/MOS > RMOS. First, in the system of ZnO, gas sensor modified by PdRh (PdRh SC/ZnO and PdRh HC/ZnO) possess enhanced H2S sensing performance with a better response and excellent low-concentration detection capability (down to 15 ppb) comparing to pure ZnO. The improved H2S sensing performance could be attributed to the good conductivity of Rh-rich frame, the high catalytic activity of PdRh bimetal and formation of Schottky barrier-type junctions and defect. Second, PdRh HC/ZnO sensor shows better response (185-1 ppm of H2S) compared to PdRh SC/ZnO sensor (108-1 ppm of H2S), which is due to the higher specific surface area of PdRh HC/ZnO and good gas diffusion of the hollow structure. This work indicate that the sensitization characteristics of PdRh bimetal HC will provide new paradigms for the future development of the high performance sensor.