Rapid Detection Method Research Articles

Development of a duplex real-time recombinase aided amplification assay for the simultaneous and rapid detection of PCV3 and PCV4

BackgroundPorcine circoviruses 3 (PCV3) and 4 (PCV4) are emerging pathogens with global implications for swine industry, disturbing the diagnosis of PCVs associated diseases due to a range of similar clinical symptoms and increasingly coinfections. A rapid and accurate method for detection of PCV3 and PCV4 is critical for controlling the transmission of associated disease.MethodsWe developed a duplex real-time recombinase aided amplification (RAA) assay for detection of both PCV3 and PCV4 simultaneously. The assay was completed within 20 min at 39℃ with the designed optimal primers and probes.ResultsThe established assay was more convenient and simpler operation compared with conventional molecular biological assays. The assay achieved a detection limit of 73.67 copies/reaction for each circovirus (at 95% probability by probit regression analysis) and showed high specificity and no cross-reactivity with other important porcine viruses (including PCV2). The intra- and inter-group coefficients of variation (CV) were ranged from 2.08 to 4.97%, indicating high stability and reliability. Comparative analysis with PCV3 and PCV4 qPCR on 60 clinical samples and artificially spiked samples indicated high congruence (the kappa value was 0.966 and 1, respectively, with p < 0.001), with only minor discrepancies, validating effectiveness of the duplex RAA assay in detecting co-infections and its suitability for preliminary clinical diagnosis of PCV3 and PCV4.ConclusionsThis study provides a robust basis for multiplex detection of veterinary pathogens using RAA technique, enhancing the field’s capacity to control PCV3 and PCV4, and supporting reliable aid for epidemiological understanding of emerging circoviruses.

Rapid Detection of Soil Available Phosphorus using Capacitively Coupled Contactless Conductivity Detection

Background: In China, the traditional method for analyzing soil available phospho-rus is inadequate for large-scale soil assessment and nationwide soil formulation demands. To address this, we propose a rapid and reliable method for soil-available phosphorus detection. The setup includes an on-site rapid pre-treatment device, a non-contact conductivity detection device, and a capillary electrophoresis buffer solution system composed of glacial acetic acid and hydroxypropyl-β-cyclodextrin. Methods: The on-site rapid pre-treatment process includes fresh soil moisture content detec-tion (moisture rapid detector), weighing (handheld weighing meter), stirring (handheld rapid stirrer), and filtration (soil rapid filter) to obtain the liquid sample, and direct injection (capil-lary electrophoresis detector). The phosphate ion detection parameters include capillary size, separation voltage, injection parameters, and electric injection. We used Liaoning brown soil, Henan yellow tidal soil, Heilongjiang black soil, and Anhui tidal soil as standard samples. Additionally, we used mathematical modeling methods and machine learning algorithms to analyze and process research data. Results and Conclusion: Following calibration with standard samples, the experimental blind test samples demonstrated conformity with the national standard method, exhibiting a relative standard deviation of less than 3%. The proposed pre-treatment device and non-contact con-ductivity detector are powered by lithium-ion batteries, rendering them ideal for extended field operations. The non-contact conductivity detector obviates the need for direct contact with test samples, mitigating environmental pollution. Furthermore, the neural network model exhibited the highest level of goodness of fit in chemical data analysis.

Signal-off colorimetric and signal-on fluorometric dual-mode aptasensor for ultrasensitive detection of Salmonella Typhimurium using graphitic carbon nitride.

Food safety is severely burdened by the prevalence of foodborne pathogens and the diseases they cause, necessitating the development of rapid, easy-to-use, highly sensitive, and reliable detection methods. Here, a signal-off colorimetric and signal-on fluorometric dual-mode detection method for Salmonella Typhimurium (S. typhimurium) was developed based on its unique interaction with aptamer DNA and graphitic carbon nitride (GCN). In the absence of a target Salmonella species, 6-carboxyfluorescein (FAM)-labeled aptamers are adsorbed on the surface of GCN primarily via a π-π interaction, resulting in reduced fluorescence of FAM through GCN-mediated quenching as well as improved peroxidase-like activity of GCN to generate intense blue color through facilitated electrostatic attraction between the negatively charged aptamer and positively charged 3,3',5,5'-tetramethylbenzidine (TMB) substrate. The introduction of S. typhimurium to the sample solution causes the detachment of the aptamer from GCN due to its higher affinity for S. typhimurium than GCN, thereby rapidly reducing the colorimetric signal and recovering the fluorescence. We successfully determined the number of S. typhimurium using this method in a remarkably short duration (10-30min), highlighting its rapidity. The limit of detection values for S. typhimurium were as low as 8 and 3CFU/mL when using colorimetric and fluorometric methods, respectively. Moreover, this method can be used to detect S. typhimurium spiked in real vegetable extract and milk with high reproducibility and reliability. This method serves as a convenient route to the rapid, sensitive, selective, and reliable detection of pathogens from complex food samples, with the potential to replace conventional yet laborious methods currently in use.

Novel hydroxy naphthol blue-based recombinase polymerase amplification for the rapid detection of Staphylococcus pseudintermedius.

Staphylococcus pseudintermedius (S. pseudintermedius) is a significant cause of pyoderma, soft tissue, urinary tract, and ear infections in cats and dogs. Bacterial culture and biochemical phenotypic assays are the gold standards for clinical diagnosis of bacteria but molecular methods have now been developed to identify and differentiate S. pseudintermedius. However, these methods require complex and expensive equipment, restricting usage in many laboratories. This study developed a rapid, specific, and sensitive detection method for S. pseudintermedius based on recombinase polymerase amplification (RPA) combined with hydroxy naphthol blue (HNB) dye. The RPA primer was designed, optimized, and subjected to amplify the spsL gene as the molecular diagnostic target. HNB dye was added to the reaction, successfully enabling the development of a colorimetric detection method for S. pseudintermedius. This RPA-HNB assay completed amplification at 37°C within 20min, with results visualized by the naked eye as a color change. All processes were completed within an hour. The assay showed the limit of detection at 1 copy per reaction, with sensitivity and specificity against S. pseudintermedius 0.98 and 1.00, respectively. Results indicated that our assay provided high sensitivity and specificity for detecting S. pseudintermedius with reduced detection time.

Development and validation of a LAMP-based method for rapid and reliable detection of Xanthomonas albilineans, the causal agent of sugarcane leaf scald

Development and validation of a LAMP-based method for rapid and reliable detection of Xanthomonas albilineans, the causal agent of sugarcane leaf scald

Review of pretreatment and analytical methods for environmental endocrine disruptors: Phthalates.

Phthalates, known as phthalate esters (PAEs), are among the most ubiquitous pervasive env7ironmental endocrine disruptors (EEDs), extensively utilized globally in various facets of modern life due to their irreplaceable role as plasticizers. The exponential production and utilization of plastic goods have substantially escalated plastic waste accumulation. Consequently, PAEs have infiltrated the environment, contaminating food and drinking water reservoirs, posing notable threats to human health. This review provides a comprehensive overview of research advancements in PAE detection and identifies key focal points from 2000 to 2022, utilizing the Web of Science Core Collection. Sample pretreatment and analytical methodologies for PAEs are examined based on bibliometric analysis findings. Pretreatment methods mainly include dispersive solid-phase extraction (DSPE), magnetic solid-phase extraction (MSPE), molecularly imprinted solid-phase extraction (MISPE) and solid-phase microextraction (SPME). Laboratory analytical methods such as gas chromatography (GC), liquid chromatograph (LC) and immunoassay have been described. Additionally, a discussion on the advantages and challenges of rapid on-site detection methods, in comparison to traditional approaches, is presented in alignment with the evolving demands of PAEs detection. Based on the current research progress, future studies can focus on the demand of rapid detection of PAEs.

Development of a one-step multiplex RT-qPCR method for rapid detection of bovine diarrhea viruses

IntroductionViral calf diarrhea poses a significant challenge to the cattle industry worldwide due to its high morbidity and mortality rates, leading to substantial economic losses. The clinical symptoms associated with various diarrhea pathogens often overlap, complicating accurate diagnosis; thus, there is an urgent need for rapid and precise diagnostic methods to improve prevention and treatment efforts. In this study, we developed a one-step multiplex reverse-transcription quantitative real-time polymerase chain reaction (mRT-qPCR) that enables the simultaneous detection of three key viral pathogens responsible for calf diarrhea: bovine kobuvirus (BKoV), bovine astrovirus (BoAstV), and bovine torovirus (BToV). However, development of accurate and rapid methods to distinguish these three viruses is helpful for the early detection, disease surveillance, and control of viral calf diarrhea.MethodsSpecific primers and minor groove binder (MGB)-based probes were designed targeting the 3D region of BKoV, ORF1 region of BoAstV, and N region of BToV. The sensitivity, specificity, and reproducibility ability were evaluated for the mRT-qPCR. Further, 80 bovine fecal samples were subjected to the mRT-qPCR, and the results were verified using conventional reverse-transcription PCR (RT-PCR) or PCR methods and sequencing methods.ResultsThis novel method demonstrated high sensitivity and specificity,achieving a detection limit of 24 copies/mL for each pathogen. Furthermore, the assay exhibited excellent reproducibility, with coefficients of variation below 1.5%, a strong linear correlation (R2 &amp;gt; 0.996), and an amplification efficiency between 90% and 110%. Validation with 80 clinical samples from both diarrheic and non-diarrheic cattle across four farms in Shanghai showed a high degree of concordance with RT-PCR, with positive detection rates for BKoV, BoAstV, and BToV at 28.75%, 8.75%, and 3.75%, respectively, highlighting the predominance of BKoV and BoAstV. Notably, this study represents the first identification of BKoV, BoAstV, and BToV in the Shanghai region.DiscussionThe mRT-qPCR is a robust, rapid, and simple tool for identifying viral pathogens associated with calf diarrhea, facilitating the development of effective prevention and control measures that are vital for the future sustainability of the cattle industry.

Rapid, sensitive, and visible RPA-LFD assay for BoHV-1 and BoHV-5.

Bovine herpesvirus (BoHV), a significant respiratory pathogen in cattle, is widely prevalent worldwide, posing a substantial economic threat to the cattle industry. In this study, we have developed a rapid on-site detection method for BoHV, termed RPA-LFD, which can carry out pathogen detection with a sensitivity of no less than 1 TCID50 within 30 min. When combined with screening, isolation, and culling measures, this approach can effectively eliminate the sources of BoHV infection, providing a scientifically feasible solution for BoHV prevention and control.

Development and validation of rapid eDNA detection method for yellow mud turtle, Kinosternon flavescens: a field study in South Texas, USA

The conservation of freshwater turtle species depends on precise and effective monitoring techniques. Environmental DNA (eDNA) analysis is a potential method for identifying cryptic and elusive turtle species in aquatic ecosystems. eDNA analysis can help to identify key regions for conservation efforts and monitor changes in population levels over time. This study aims to evaluate the effectiveness of a rapid eDNA detection method for the yellow mud turtle (Kinosternon flavescens, an indicator species that is endangered in some states in the USA), which inhabits local oxbow lakes (e.g., resacas) in Cameron County, South Texas. A species-specific nested PCR assay was designed to enhance the detection of yellow mud turtle species. Water samples were collected from five locations within Cameron County for the detection of yellow mud turtle eDNA. Our results revealed the presence of yellow mud turtles in two out of the five surveyed locations. Our study shows great potential for eDNA monitoring for yellow mud turtle species. This study also provides insights on using eDNA monitoring to protect yellow mud turtle species and recommendations for future research and conservation initiatives.

PCR-based detection technique and gamma irradiation strategies for managing Ralstonia solanacearum-induced brown rot of potato

Purpose The study focused on developing a rapid PCR-based detection method and employing gamma irradiation techniques to manage Ralstonia solanacearum, aiming to produce brown rot-free export-quality potatoes. This initiative seeks to enhance potato exports from Bangladesh. Materials and Methods Samples of potato tubers and soil were collected from various commercially significant potato-growing areas, resulting in a total of 168 Ralstonia solanacearum isolates from potato tubers and soil across 12 regions. The detection of R. solanacearum in the enriched tuber extract and soil were conducted using the primer pairs (PS-1, PS-2) and (759, 760). For the gamma irradiation experiment, petri dishes containing R. solanacearum cultures were subjected to different doses of gamma rays at the Bangladesh Institute of Nuclear Agriculture using a 60Co source. The irradiation doses applied to the samples were 0–6.0KGy. Results Morphological identification based on pink/light red colonies on TTC medium was confirmed R. solanacearum in 148 isolates. PCR using species-specific primers (PS-1/PS-2) and (759, 760) verified 26 isolates (14 tubers, 12 soil), producing 553 bp and 281 bp fragments in latently infected tubers and soil samples respectively. Gamma irradiation at 2.5 kGy damaged R. solanacearum’s DNA and cells, preventing brown rot, while higher doses eliminated it entirely. This offers a promising strategy to enhance safety of stored potatoes, potentially mitigating economic losses from this quarantine pathogen. Conclusion The study developed a PCR detection method and gamma irradiation techniques to manage R. solanacearum, enhancing the export quality of potatoes.

A lanmodulin-based fluorescent assay for the rapid and sensitive detection of rare earth elements.

Sensitive and rapid detection methods for rare earth elements (REEs), including lanthanides (Lns), will facilitate the mining and recovery of these elements. Here, we innovated a rapid, highly selective and sensitive fluorescence detection method for Lns, based on Hans-Lanmodulin, a newly discovered protein with high selectivity and binding affinity for rare earth elements. By labelling the fluorescein moiety FITC onto Hans-Lanmodulin, named as FITC-Hans-LanM. When rare earth ions are present in solution, FITC-Hans-LanM will specifically bind rare earth ions undergoing a conformational change from a disordered state to a dimer, in which the FITC molecules come close to each other, resulting in decreasing fluorescence intensity or even quenching. The assay was responsive to light, medium and heavy rare earth ions. The fluorescence signal has a good linear relationship with Nd3+ concentration in the range of 1-20 nM. The detection limit of the method was 0.512 nM, within 1 min. This method could become a useful technique for the detection and quantification of rare earth elements in environmental and industrial samples.

Development of a Portable Rapid Detection Method for Porcine Epidemic Diarrhea Virus Using Reverse Transcription-Recombinase-Aided Amplification Technology.

Porcine epidemic diarrhea virus (PEDV) continues to spread globally, causing clinical symptoms in piglets, including watery diarrhea, vomiting, and dehydration. Its exceptionally high morbidity and mortality rate contributes significantly to the economic losses of the swine industry. The continuous genetic mutations of PEDV have compromised the effectiveness of classical strain vaccines. Early detection and accurate diagnosis are therefore crucial for controlling its further spread. Developing a detection method that is user-friendly, highly sensitive, and efficient is crucial for disease control. In this study, a point-of-care rapid detection method for PEDV was successfully established using reverse transcription-recombinase-aided amplification (RT-RAA) technology. This method enables results to be obtained within 20 min of amplification at a constant temperature of 42 °C. It demonstrates high sensitivity, with a detection limit as low as 1 copy/μL, and shows strong specificity, with no cross-reactivity observed with seven other common swine pathogens. When applied to clinical samples, the results were 100% consistent with those obtained by RT-qPCR. This method is distinguished by its portable instrumentation and simple operation, making it particularly suitable for resource-constrained settings.

A practical fluorometric and colorimetric dual-mode sensing platform based on two-dimensional porous organic nanosheets for rapid determination of trifluralin.

Trifluralin, a widely used dinitroaniline herbicide, poses significant toxic risks, necessitating the development of rapid detection methods for food safety. In this study, we prepared ultrathin two-dimensional triphenylamine porous organic nanosheets (TPA-PONs) through a facile liquid-phase exfoliation process. The TPA-PONs, characterized by their exceptional fluorescence properties and nanoscale thickness (1.65 ± 0.3 nm), demonstrated a remarkable fluorescence quenching response upon exposure to trifluralin. Spectroscopic analysis combined with DFT calculations revealed that the quenching mechanism is driven by electron and energy transfer. TPA-PONs-based fluorescence sensor exhibited a linear response to trifluralin concentrations ranging from 0.01 to 10.0 μmol L-1 with a limit of detection as low as 3.50 nmol L-1. Additionally, the sensor was applied to detect trifluralin residues in vegetables, achieving recoveries of 89.08-102.84%. To facilitate on-site detection, a novel TPA-PONs-based colorimetric film sensor has been developed, enabling visual analysis of trifluralin using a smartphone. This dual-mode sensing platform holds significant potential for enhancing food safety monitoring.

EVALUATION OF THE APPLICABILITY OF THE O.K.N.V.I. RESIST-5 AND THE KPC&amp;amp;MBL&amp;amp;0XA-48 DISK TESTS IN A ROUTINE MICROBIOLOGY LABORATORY

Background: The global spread of carbapenemase-producing Enterobacterales (CPE) and the increasing emergence of clinical Enterobacterales harboring multiple carbapenemases of different molecular classes have prioritized the use of rapid molecular detection methods in routine microbiology laboratories. The aim of this study was to evaluate the applicability of the immunochromatographic O. K.N.V.I. RESIST-5 and the KPC&amp;MBL&amp;0XA-48 disc tests in a clinical microbiology laboratory. Material and methods: The tests were performed with 50 CPE belonging to 8 species and producing 7 molecularly characterized carbapenemases. Six of these isolates carried two different carbapenemases. To assess the specificity of the assays, 18 non-carbapenemase-producing but carbapenem-resistant Enterobacterales (non-CP CRE) were also included. Both tests were performed from a common overnight culture on Mueller-Hinton agar with inoculum harvested around an ertapenem disk. Results: The O.K.N.V.I. RESIST-5 correctly detected all 56 carbapenemases, including KPC-2 in Klebsiella pneumoniae; OX-48 in Serratia marcescens, Citrobacter freundii, Enterobacter hormaechei and K. pneumoniae; NDM-1 in Escherichia coli, Morganella morganii, E. hormaechei, C. freundii, S. marcescens and K. pneumoniae; VIM-1 in Proteus mirabilis; VIM-4 in C. freundii and S. marcescens; VIM-86 with and without NDM-1 in Providencia stuartii, and NDM-5 with and without OXA-232 in K. pneumoniae. The KPC&amp;MBL&amp;0XA-48 disc tests correctly confirmed KPC, OX-48-like and most MBL except VIM in P. mirabilis. Furthermore, the combination disc tests failed to detect OXA-48-like in pairs with MBL in K. pneumoniae. Conclusions:The O.K.N.V.I. RESIST-5 multiplex lateral assay is an excellent test for rapid diagnostic of CPE in routine microbiology laboratories. It is easy to handle and provides results with 100% sensitivity and specificity when an inoculum around ertapenem disc from routine antibiogram was used.

Development and evaluation of optimized PCR and indirect ELISA for the detection of Morganella morganii in dairy cows.

Morganella morganii (M. morganii) is a Gram-negative opportunistic pathogen, whose increasing virulence and antibiotic resistance negatively impact dairy cow health and productivity, raising concerns in livestock health management. To mitigate this risk, rapid and reliable diagnostic methods for detection are essential. Currently, detection methods for M. morganii are underdeveloped, prompting us to develop both pathogenic and serological detection methods, including an optimized PCR technique and an indirect enzyme-linked immunosorbent assay (I-ELISA). The optimized PCR method utilized bacterial suspensions directly as templates, bypassing the need for DNA extraction and thereby allowing the direct detection of M. morganii in fecal samples. Primer concentrations and annealing temperatures were optimized to minimize primer dimer formation, ensuring high specificity. Clinical evaluation was conducted using 771 fecal and nasal fluid samples collected from dairy farms in five regions. The I-ELISA method was developed using M. morganii lipoprotein (LPP) antigen. Parameters such as antigen coating, blocking conditions, and antibody dilution were optimized to improve specificity. Stability and reproducibility were validated through intra- and inter-assay tests. A total of 476 serum samples from dairy cows were tested to assess the method's clinical applicability. The optimized PCR method demonstrated high sensitivity and specificity, achieving a detection threshold of 0.2 CFU/μL. Clinical testing revealed a positivity rate of 1.4% among 771 fecal and nasal fluid samples. The I-ELISA method showed excellent stability and reproducibility, confirmed through intra- and inter-assay consistency. In testing 476 dairy cow serum samples, the positivity rate for M. morganii was 5.9%. These results indicate the utility of I-ELISA as a reliable serological diagnostic tool. The PCR and I-ELISA methods collectively offer practical solutions for the early clinical diagnosis of M. morganii infections in dairy cows. The PCR technique's efficiency and sensitivity make it ideal for pathogen detection in fecal samples, while the I-ELISA method provides a robust platform for serological analysis. Together, these tools enable timely intervention, contributing to improved livestock health management and mitigating the negative impacts of M. morganii on dairy cow productivity. Future research may focus on further refining these techniques and exploring their applications in broader livestock management contexts.

Construction of an electrochemical sensor for the detection of methyl parathion with three-dimensional graphdiyne-carbon nanotubes.

To enhance the application performance of graphdiyne (GDY) in electrochemical sensing, carbon nanotubes (CNTs) were grown in situ to construct three-dimensional nanoarchitectures of GDY-CNTs composites. GDY-CNTs showed superior electrochemical properties and detection response to MP when compared withGDY, as the in situ growth of CNTs significantly increased the electrode surface area and enhanced the electron transfer process. GDY-CNTs were successfully used to construct electrochemical sensors for methyl parathion (MP). The proposed sensor exhibited a wide linear relationship for MP ranging from 0.09 to 64.6µM with a detection limit of 0.05µM. Moreover, the sensor also showed good stability and acceptable reproducibility, which provided a feasible method for rapid and accurate detection of MP in real samples. This work provides an effective application of graphdiyne in electrochemical sensing with constructed three-dimensional GDY-CNTs.

Surface-Enhanced Raman Spectroscopy for Nitrite Detection.

Nitrite is an important chemical intermediate in the nitrogen cycle and is ubiquitously present in environmental and biological systems as a metabolite or additive in the agricultural and food industries. However, nitrite can also be toxic in excessive concentrations. As such, the development of quick, sensitive, and portable assays for its measurement is desirable. In this review, we summarize the working principles and applications of surface-enhanced Raman spectroscopy (SERS) as a rapid, portable, and ultrasensitive method for nitrite detection and showcase its applicability in various water, food, and biological samples. The challenges and opportunities for future developments are also discussed.

A rapid and highly sensitive fluorescence immunochromatographic test strip for pepsin detection in human hypopharyngeal saliva.

Pepsin serves as a potential biomarker for laryngopharyngeal reflux disease (LPRD). The reported methods for detecting pepsin still have limitations, such as long reaction times and low sensitivity. Therefore, it is crucial to develop a rapid, simple and sensitive detection method. In this study, a fluorescence immunochromatographic test strip was designed for point-of-care diagnostics of LPRD. To obtain optimal fluorescence immunochromatographic conditions, key experimental factors, including microsphere particle size, binding pH, and resuspension dilution ratio, were systematically evaluated. The optimal fluorescent microsphere size was determined to be 300 nm, the most suitable reaction pH was 8.0, and the ideal resuspension solution to storage solution ratio was 1 : 4. Under these optimal conditions, the sensor had a linear range of 2.5-100.0 ng mL-1 and a detection limit of 1.9 ng mL-1. The relative standard deviation was below 15% for both intra- and inter-batch reproducibility. Under accelerated damage conditions at 37 °C, the test value of the test strip could be kept basically unchanged for 14 days. There was no cross-reactivity of the test strip with pepsinogen I, pepsinogen II and other interferents. In the actual sample detection, the recovery rate was between 85% and 115%. Furthermore, the proposed method was demonstrated to be green and to exhibit strong applicability based on the evaluation using the AGREEprep and the BAGI. In addition, the method has the advantages of high sensitivity, accuracy, greenness and applicability, which can meet the needs of rapid quantitative on-site detection.

Preparation of ofloxacin molecularly imprinted polymer Raman sensor based on magnetic graphene oxide.

Ofloxacin is a commonly used quinolone antibiotic that is also used as a feed supplement in livestock production and in plant disease prevention and treatment. However, the excessive use and abuse of ofloxacin will accumulate along the food chain and endanger human health. Therefore, the development of a simple, rapid, and sensitive detection method for the determination of ofloxacin is critical. Herein, a detection method combining molecularly imprinted magnetic solid-phase extraction (MISPE) and surface-enhanced Raman spectroscopy (SERS) was developed for the detection of ofloxacin. Graphene oxide supported by magnetic beads was synthesized by a one-pot method, producing what was subsequently referred to as magnetic graphene oxide (MGO), and a molecularly imprinted membrane was synthesized on its surface by exploiting the ability of dopamine to self-polymerize under alkaline conditions. MGO@MIPs were obtained as the adsorbent for magnetic solid-phase extraction, which was used for the extraction and enrichment of ofloxacin in complex sample matrix, and then quantitative analysis was conducted by SERS. The developed method exhibited an excellent linear relationship with respect to ofloxacin concentration (10-5 to 102μgmL-1), with a detection limit of 9.7 × 10-6μgmL-1 in ultrapure water. Blank honey, milk, and pork samples spiked with ofloxacin at concentrations of 0.005, 0.1, 1, and 10μgmL-1 were extracted and determined using the developed method, with recoveries ranging from 93.1% to 105.6%. The results support the strong application prospects for the method, demonstrating simple and time-efficient operation and high accuracy.

Rapid and Simultaneous Detection of Petroleum Hydrocarbons and Organic Pesticides in Soil Based on Electronic Nose.

The rapid detection of petroleum hydrocarbons and organic pesticides is an important prerequisite for precise soil management. It is also a guarantee for soil quality, environmental safety, and human health. However, the current rapid detection methods are prone to sample matrix interference, complex development processes, short lifespan, and low detection accuracy. Moreover, they face difficulties in achieving simultaneous detection of petroleum hydrocarbons and organic pesticides. In this paper, we developed an electronic nose system for the simultaneous detection of petroleum hydrocarbons and organic pesticides in soil based on gas technology, which includes a sampling module and recognition model. The developed sampling module can simultaneously acquire the odor signals of petroleum hydrocarbons and organic pesticides in soil. The established recognition model can quickly distinguish between healthy soil, soil contaminated by petroleum hydrocarbons, and soil contaminated by organic pesticides. It can also achieve specific recognition of pesticide types and petroleum types. The performance of the developed electronic nose system was verified for real soil, petroleum products, and organic pesticides. The experiment shows that the developed electronic nose system has an accuracy of 100% for three tasks: soil conditions identification, pesticide types identification, and petroleum types identification.