Recent Advances in the Rapid Detection and Performance Evaluation Methods of Detergent Additives for Gasoline

Although detergent additives for gasoline have been widely commercialized,their formulas are often kept confidential and there is still no standardized method for quickly detecting the main active ingredients and evaluating their effectiveness,which makes their regulation difficult.An overview of the current state of the development and application of detergent additives for gasoline in China and other regions,as well as a review of the rapid detection and performance evaluation methods available for analyzing detergent additives are given herein.The review focuses on the convenience,cost,efficiency,and feasibility of on-site detection and the evaluation of various methods,and also looks into future research directions,such as detecting and evaluating detergent additives in ethanol gasoline and with advanced engine technologies.

Establishment of a rapid detection method of Ureaplasma urealyticum based on recombinant polymerase amplification

Ureaplasma urealyticum(UU),is one of the most vital pathogens causing genitourinary tract infections of the body,and it can result in poor maternal and perinatal outcomes.The aim of this study was to establish a method to detect Ureaplasma urealyticum based on recombinant polymerase amplification(RPA)technique.Specific primers and probes were designed according to the 16sRNA gene sequence of Ureaplasma urealyticum.Six pathogens were detected for real-time fluorescence RPA specificity verification,including Mycoplasma hominis(MH),Chlamydia trachomatis(CT),Neisseria gonorrhoeae(NG),Staphylococcus aureus,Escherichia coli,and Lactobacillus vaginalis.The sensitivity of the method was performed by gradient dilution of the extracted template.A total of 60 clinical samples were detected by the established real-time fluorescence RPA.Detection of Ureaplasma urealyticum can be completed within 20 minutes at 39°C using established RPA method.The minimum detection limit of Ureaplasma urealyticum by real-time fluorescence RPA was 3 pg.The evaluation of 60 clinical samples proved that RPA method was feasible.A high specificity,sensitivity,simplicity and rapidity method for Ureaplasma urealyticum detection was successfully established based on the real-time fluorescence RPA method.

Rapid detection of Pseudomonas aeruginosa by cross priming amplification

Pseudomonas aeruginosa(PA)is an opportunistic pathogen of humans and animals and a common source of nosocomial infections especially of the respiratory tract.Pseudomonas aeruginosa is also a major bacterial disease of poultry and in particular,eggs and newly hatched chicks.In this study,we developed a simple,accurate and rapid molecular detection method using cross priming amplification(CPA)with a nucleic acid test strip to detect P.aeruginosa.The assay efficiently amplified the target gene within 45 min at 62℃only using a simple water bath.The detection limit of the method was 1.18x 102 copiesμL^-1 for plasmid DNA and 4.4 CFU mL^-1 for bacteria in pure culture,and was 100 times more sensitive than conventional PCR.We screened 83 clinical samples from yellow-feather broiler breeder chickens and hospitalized/treated dogs and cats using CPA,PCR and traditional culture methods.The positive sample ratios were 15.3%(13/83)by CPA,13.3%(11/83)by PCR and 12.1%(10/83)by the culture method.The established CPA method has significant advantages for detecting P.aeruginosa.The method is easy to use and possesses high specificity and sensitivity without the requirements of complicated experimental equipment.The PA-CPA assay is especially fit for outdoor and primary medical units and is an ideal system for the rapid detection and monitoring of P.aeruginosa.

In vitro Selection of DNA Aptamers and Fluorescence-Based Recognition for Rapid Detection Listeria monocytogenes

Aptamers are specific nucleic acid sequences that can bind to a wide range of nucleic acid and non-nucleic acid targets with high affinity and specificity. Nucleic acid aptamers are selected in vitro from single stranded DNA or RNA ligands containing random sequences of up to a few hundred nucleotides. Systematic evolution of ligands by exponential enrichment （SELEX） was used to select and PCR amplify DNA sequences （aptamers） capable of binding to and detecting Listeria monocytogenes, one of the major food-borne pathogens. A simplified affinity separation approach was employed, in which L. monocytogenes in exponential （log） phase of growth was used as the separation target. A fluorescently-labeled aptamer assay scheme was devised for detecting L. monoeytogenes. This report described a novel approach to the detection of L. monocytogenes using DNA aptamers. Aptamers were developed by nine rounds of SELEX. A high affinity aptamer was successfully selected from the initial random DNA pool, and its secondary structure was also investigated. One of aptamers named e01 with the highest affinity was further tested in aptamer-peroxidase and aptamer-fluorescence staining protocols. This study has proved the principle that the whole-cell SELEX could be a promising technique to design aptamer-based molecular probes for dectection of pathogenic microorganisms without tedious isolation and purification of complex markers or targets.

Enzyme Inhibition Rate Method for Rapid Detection of Organophosphorus and Carbamate Pesticides in Cowpea

[Objectives ] The paper was to explore enzyme inhibition rate method for rapid detection of organophosphorus and carbamate pesticides in cowpea. [ Methods ] Acetylcholinesterase （ACHE） was added to cowpea extract, to determine the inhibition rate of extract against enzyme. The influences of different sampiing methods and sampling parts on detection results were compared. [ Results] The positive rate of standard sampling was 18.18% higher than that of non-stand- ard sampling, and the positive rate of samples collected from cowpea tail was 16.67% higher than that collected from other parts. [ Condmions] Enzyme inhibi- tion rate method is suitable for rapid detection of organophosphorus and carbamate pesticides in cowpea.

Dengue virus infection:A review of advances in the emerging rapid detection methods

Dengue virus infections are increasing worldwide generally and in Asia,Central and South America and Africa,particularly.It poses a serious threat to the children population.The rapid and accurate diagnostic systems are essentially required due to lack of effective vaccine against dengue virus and the progressive spread of the dengue virus infection.The recent progress in developing micro-and nano-fabrication techniques has led to low cost and scale down the biomedical point-of-care devices.Starting from the conventional and modern available methods for the diagnosis of dengue infection,this review examines several emerging rapid and point-of-care diagnostic devices that hold significant potential for the progress in smart diagnosis tools.The given review revealed that an effective vaccine is required urgently against all the dengue virus serotypes.However,the rapid detection methods of dengue virus help in early treatment and significantly reduce the dengue virus outbreak.

Rapid Detection of Fat Content in Chenopodium quinoa Willd by Near Infrared Spectroscopy

This study was conducted to find a method for rapid determination of fat content in complete quinoa （ Chenopodium quinoa Willd） seeds. The near infrared spectra of 100 quinoa samples were collected, and a mathematic model was built using the near infrared spectra, so as to perform prediction. The results showed that within the wavelength range of 1 0 000-4 000 cm ^-1 , the quantification model of fat content built by first derivative ＋vector normalization spectral pre-processing had better calibration and prediction effects, and showed a determination coefficient of cross validation （ r cv^ 2 ） of 0.939 3 and a determination coefficient of validation （ rval^2 ） of 0.923 5. The near infrared spectral model of fat could be used for rapid detection of fat contents in quinoa.

Establishment of Recombinase Polymerase Amplification for Rapid Detection of Spring Viremia of Carp Virus(SVCV)

[Objective]The paper was to develop a rapid method for the detection of spring Viremia of carp virus(SVCV).[Method]The specific primers were designed by targeting the G gene of SVCV.The recombinase polymerase amplification(RPA)assay for detecting SVCV was estab-lished by optimizing the reaction conditions.The optimal amplification temperature of RPA assay was 30℃,and the test could be finished within 20 min.[Result]The method was specific with no cross-reaction with other common fish infectious viruses.Sensitivity test showed that the lowest detection limit of the method was 89.2 copies/μL,higher than that of traditional RT-PCR.Moreover,a total of 80 clinical samples were detected by RPA and RT-PCR,respectively.The weak positive samples tested by RT-PCR could be detectable with RPA,indicating that RPA assay could be used in clinical detection.[Conclusion]The method established is rapid,simple,specific and sensitive for testing SVCV,and it will be widely used in grassroots laboratory and on-site inspection.

Synthetic Biology Construct of Ebola Virus in Bacteria Surrogate Is Stable and Safe for Rapid Detection Studies in a BSL-2 Laboratory Setting

Rapid detection of virulent pathogens during an outbreak is critical for public health advisories and control of the disease in a population. While many molecular techniques for point of care and clinical diagnosis abound, the US experience with the COVID-19 testing in the early stages of the pandemic underscores the critical importance of determining the appropriate target gene(s) with in-built controls that reliably detect pathogens with high sensitivity and specificity. Assays and research for diagnostics and therapy could be slowed during an epidemic because access to the required BSL-3 and BSL-4 laboratories are limited. So, during the 2014 West Africa Ebola outbreak, we tested the hypothesis that using synthetic cDNA of Ebolavirus in a bacteria surrogate (fit for all lab settings), would remain unmutated and safe after several generations, serving as an effective positive control in research settings, self test and point-of-care detection platforms. Primers were designed for the detection and quantification of the nucleoprotein (NP) gene of the 2014 Makona Ebola strain (KR781608.1, 733 - 1332 bp). To test the stability of artificially inserted translation arrest in the Orf of the model gene, it was edited to include three STOP codons in the RNA transcript using SNAP GENE. The segment was then spliced into a high copy number plasmid, cloned into One ShotTM TOP10 Escherichia coli (Invitrogen), and tested for stability and safety by periodic subculture, extraction and sequencing. Unlike COVID-19, rapid detection of blood-borne etiologies like Ebola requires optimized protocols for blood matrix. Using real-time PCR and newly designed primer pairs, the EBOV surrogate was detected and enumerated in human blood and regular broth and buffers. Based on aligned sequence analysis, the EBOV synthetic NP gene was stable (>99.9999% similarity coefficient) for at least 3 months. Detection sensitivity in broth and blood was at least 100 cells/ml or about 5.8 × 103 to 7.3 × 103 virion equivalents per ml. While the developments of transcription-and-replication-competent virus like particles (trVLP) have made it possible to study the infection and replication cycles of virulent pathogens in BSL-2 laboratories, the simplicity of our model and the reproducibility of detection and enumeration show the utility of synthetic bio-components as positive controls for point of care diagnostic tools. The inserted stop codons remained intact after many generations, suggesting that expressed virulent proteins can be easily silenced in synthetic biology models for research in BSL-1 and 2 and a wide range of pathogens. Synthetic bio-components can thereby aid further research by reducing costs and improving safety for workers and stakeholders.

A Device for Rapid Detection of Dithiocarbamate Pesticide Residues in Fruits

Based on the chemical properties of dithiocarbamate pesticides,a device for rapid detection was developed in the paper,and the experimental conditions were optimized. Dithiocarbamate residues in fruits were successfully detected using molecular absorption spectro-photometry,and the recovery rate was over 80%.The rapid detection method was simple to operate with low cost,and was conducive to application in basic level and enterprise laboratories.

ZnO/PANI nanoflake arrays sensor for ultra-low concentration and rapid detection of NO_(2)at room temperature

With the development of environmental monitoring,it is urgent to establish NO_(2)sensor with good sensing performance.Compared with the traditional NO_(2)sensors made of metal oxides,NO_(2)sensors made of n-p heterostructure nanocomposites have good sensing performance in detection limit and operating temperature.ZnO nanoflake arrays with polyaniline film grown on the surface were prepared on ceramic tubes by hydrothermal and vapor diffusion method.The gas-phase diffusion method can control the heterostructure by adjusting the diffusion time.At room temperature(25℃),the construction of rich n-p heterogeneous interface enables the sensor prepared by the nanocomposite to respond to NO_(2),showing the sensing performance with the response value of 28.00 to10.00×10^(-6)NO_(2);the detection limit improved to0.01×10^(-6)and the recovery time of 18 s.In this work,the sensing mechanism of NO_(2)at heterogeneous interface is analyzed,which provides a promising material for the detection of low concentration NO_(2)at room temperature.

Filtration assisted pretreatment for rapid enrichment and accurate detection of Salmonella in vegetables

Rapid detection of target foodborne pathogens plays more and more significant roles in food safety,which requires the efficiency,sensitivity,and accuracy.In this research,we proposed a new st rategy of isothermal-molecular-amplification integrated with lateral-flow-strip for rapid detection of Salmonella without traditional enrichment-culture.Th e designed syringe-assisted-filtration can contribute to simultaneous collection and concentration of target bacterium from vegetable samples in just 3 min,resolving the drawbacks of traditional random sampling protocols.After simple and convenient ultrasonication,samples can be directly amplified at 39℃ in 25 min and the amplicons are qualitatively and quantitatively analyzed with the designed lateral-flow-strip in 5 min.Finally,satisfied results have been achieved within 40 min,which greatly improve the efficiency while the accuracy is also guaranteed.Furthermore,all detection steps can be completed under instrument-free conditions.This method will hold great promise for target pathogen detection in the resource-limited district,or for emergency on-site identification.

Safety issues and new rapid detection methods in traditional Chinese medicinal materials

The safety of traditional Chinese medicine(TCM) is a major strategic issue that involves human health. With the continuous improvement in disease prevention and treatment, the export of TCM and its related products has increased dramatically in China. However, the frequent safety issues of Chinese medicine have become the ‘bottleneck' impeding the modernization of TCM. It was proved that mycotoxins seriously affect TCM safety; the pesticide residues of TCM are a key problem in TCM international trade; adulterants have also been detected, which is related to market circulation. These three factors have greatly affected TCM safety. In this study, fast, highly effective, economically-feasible and accurate detection methods concerning TCM safety issues were reviewed, especially on the authenticity, mycotoxins and pesticide residues of medicinal materials.

Rapid detection of pesticide residues in Chinese herbal medicines by molecularly imprinted membrane electrospray ionization mass spectrometry

Chinese herbal medicines(CHMs)play an increasingly important role in the field of medicine and affects public health in the world.Although more and more strict has been employed to ensure the quality and safety of CHMs,pesticide residues in CHMs remain a serious issue and are the bottleneck for the global development of CHMs.In this work,we applied molecularly imprinted membrane electrospray mass spectrometry(MIM-ESI MS)for rapid detecting 4 classes of pesticide residues in CHMs,including organophosphorus(OPP),carbamates,pyrethroids and neonicotinoids in CHMs.Compared with our previous ambient ionization method MESI,MIM-ESI is capable of achieving a~50-fold increase in the detection limit of conventional analytical methods owing to the specificity recognition and unique enrichment of MIM.The optimal experimental conditions were determined,and the method was further validated for its sensitivity and specificity.Our data showed that MIM-ESI MS is applicable for the direct quantitation of pesticide residues in CHMs.This detection technology may help to ensure the quality of CHMs in the future.

Rapid detection of organophosphorus pesticide residue on Prussian blue modified dual-channel screen-printed electrodes combing with portable potentiostat

A novel electrochemical method for the rapid detection of organophosphorus pesticide residues was realized on a dual-channel screen-printed electrode （DSPE） that was integrated with a portable smartphone-controlled potentiostat. The two carbon working channels of DSPE were first modified by electrodepositing of Prussian blue. The channels were then modified with acetylcholinesterase （ACHE） via Nation. The inhibition ratio of AChE was detected by comparing the electrical current of acetylthiocholine （ATCh） that was catalyzed by the enzyme electrodes with （channel 1） and without （channel 2） organophosphorus pesticide. Inhibition ratios were related with the negative logarithm of the organophosphorus pesticide （trichlorfon, oxamyl, and isocarbophos） concentrations at optimum experimental conditions （pH 6.9 of electrolyte, 0.2V working potential, 2.5μL AChE modification amount, and 15 min inhibition time）. The linear equations were 1%=32.301gC＋ 253.3 （R=0.9750） for isocarbophos, I% = 35.991gC＋ 270.1 （R = 0.9668） for chlorpyrifos, and 1% = 33.701gC＋ 250.5 （R = 0.9606） for trichlorfon. The detection limits were calculated as 10-7 g/mL. Given that the inhibition ratios were only related with pesticide concentration and not with pesticide species, the proposed electrodes and electrometer can rapidly detect universal organophosphorus pesticides and assess pesticide pollution.

Rapid detection of aflatoxin B_(1) in paddy rice as analytical quality assessment by near infrared spectroscopy

A rapid identification method for aflatoxin B_(1) in paddy rice samples was developed by using near infrared spectroscopy under a wavelength range of 1000-2500 nm.Eighty paddy rice samples were collected from both natural and artificial infection with aflatoxin B_(1) to build the calibration models based on the partial least square regression method.The best predictive model to detect aflatoxin B_(1) in paddy rice was obtained using standard normal variate detrending spectra,with a correlation of 0.850,and a standard error of prediction of 3.211%.Therefore,the result showed that near infrared spectroscopy could be a useful instrumental method for determining aflatoxin B_(1) in paddy rice.The near infrared spectroscopy methodology can be applied to the monitoring of aflatoxin fungal contamination in postharvest paddy rice during storage and may become a powerful tool for the safety of grain and grain products.

Recent progress on microfluidic biosensors for rapid detection of pathogenic bacteria

Rapid on-site detection of pathogenic bacteria with high sensitivity and specificity is becoming an urgent need in public health assurance, medical diagnostics, environmental monitoring, and food safety fields. Despite being reliable and widely used, the existing methods of bacteria detection are cumbersome and time-consuming, which is not conducive to field detection. Microfluidic lab-on-a-chip technology has provided a detective tool for various analytes, due to its miniaturization, portability and low reagent consumption. Within this progress report, advances in the bacteria detection using microfluidic biosensors were discussed. Typical methods for pathogenic bacteria capture, separation and detection were introduced respectively in the first part. Then key applications of microfluidic biosensor-based rapid bacteria detection were presented. Finally, we made a conclusion and discussed possible research prospects in aspects of microfluidic biosensors for rapid detection of pathogenic bacteria.

Study on PCR rapid molecular detection technique of Meloidogyne vitis

Meloidogyne vitis is a new root-knot nematode parasitic on grape root in Yunnan Province,China.In order to establish a rapid,reliable and specific molecular detection method for M.vitis,the species-specific primers were designed with rDNA-ITS(ribosomal DNA internal transcribed spacer)gene fragment as the target.The reaction system was optimized and the reliability,specificity and sensitivity of primer were testified,therefore,a rapid PCR detection method for M.vitis was established.The result showed that the optimal annealing temperature of the primers was 53℃,which was suitable for the detection of different life stages of M.vitis.Specificity test showed that the specific fragment size of 174 bp was obtained from M.vitis,but other five non-target nematodes did not have any amplification bands,thus effectively distinguish M.vitis and the other five species,and could specifically detect the M.vitis from mixed populations.Sensitivity test showed that this PCR technique could detect the DNA of a single second-stage juvenile(J_(2))and 10^(-4)female.Futhermore,this PCR technique could be used to detect directly M.vitis from soil samples.The rapid,sensitive and specific PCR molecular detection technique could be used for the direct identification of a single J_(2)of M.vitis and the detection of M.vitis in mixed nematode populations and the detection of two J_(2)s or one male in 0.5 g soil samples,which will provide technical support for the investigation of the occurrence and damage of M.vitis and the formulation of efficient green co ntrol strategies.

Rapid detection of influenza A(H1N1)virus by conductive polymer-based nanoparticle via optical response to virus-specific binding

A recurrent pandemic with unpredictable viral nature has implied the need for a rapid diagnostic technology to facilitate timely and appropriate countermeasures against viral infections.In this study,conductive polymer-based nanoparticles have been developed as a tool for rapid diagnosis of influenza A(H1N1)virus.The distinctive property of a conductive polymer that transduces stimulus to respond,enabled immediate optical signal processing for the specific recognition of H1N1 virus.Conductive poly(aniline-co-pyrrole)-encapsulated polymeric vesicles,functionalized with peptides,were fabricated for the specific recognition of H1N1 virus.The low solubility of conductive polymers was successfully improved by employing vesicles consisting of amphiphilic copolymers,facilitating the viral titer-dependent production of the optical response.The optical response of the detection system to the binding event with H1N1,a mechanical stimulation,was extensively analyzed and provided concordant information on viral titers of H1N1 virus in 15 min.The specificity toward the H1N1 virus was experimentally demonstrated via a negative optical response against the control group,H3N2.Therefore,the designed system that transduces the optical response to the target-specific binding can be a rapid tool for the diagnosis of H1N1.

RAPID DETECTION OF ONCOGENE AMPLIFICATION IN PARAFFIN SECTIONS OF BREAST CARCINOMAS USING QUANTITATIVE DIFFERENTIAL PCR AND FLUORESCENT DNA TECHNOLOGY

Gene amplification is a common mechanism of oncogene activation and contributes to tumor progression. Analysis of such genetic alterations are relevant to the understanding of tumor genetics and could provide prognostic information for the individual patient. Standard analytical approaches using Southern blot and slot blot require a large amount of good