In order to enhance the flavor of chafing dish and increase the attraction of consumers,the poppy shell is reported to be illegally added to the condiments of chafing dish.In this research,a rapid,simple,and convenien...In order to enhance the flavor of chafing dish and increase the attraction of consumers,the poppy shell is reported to be illegally added to the condiments of chafing dish.In this research,a rapid,simple,and convenient method based on the classic immunochromatographic lateral flow strip(LFS)with gold nanoparticles(GNPs)labeling was developed for easy monitoring of morphine(MOP),an effective component of poppy shell.Under optimized conditions,this developed LFS can well realize the detection of target MOP in the condiments of chafing dish in less than 10 min without any complicated pre-treatments.The limit of detection(LOD)can be achieved as low as 0.1 ppb for standard MOP or the MOP spiked condiments of chafing dish.All these results of the research strongly demonstrate that this established LFS method can be successfully applied in practical rapid and accurate on-site screening of poppy shell in condiments of chafing dish.展开更多
Rapid,sensitive,point-of-care detection of pathogenic bacteria is important for food safety.In this study,we developed a novel quantum dot nanobeads-labelled lateral flow immunoassay strip(QBs-labelled LFIAS)combined ...Rapid,sensitive,point-of-care detection of pathogenic bacteria is important for food safety.In this study,we developed a novel quantum dot nanobeads-labelled lateral flow immunoassay strip(QBs-labelled LFIAS)combined with strand displacement loop-mediated isothermal amplification(SD-LAMP)for quantitative Salmonella Typhimurium(ST)detection.Quantum dot nanobeads(QBs)served as fluorescence reporters,providing good detection efficiency.The customizable strand displacement(SD)probe was used in LAMP to improve the specificity of the method and prevent by-product capture.Detection was based on a sandwich immunoassay.A fluorescence strip reader measured the fluorescence intensity(FI)of the test(T)line and control(C)line.The linear detection range of the strip was 10^(2)–10^(8) colony forming units(CFU)·mL^(-1).The visual limit of detection was 10^(3) CFU·mL^(-1),indicating that the system was ten-fold more sensitive than AuNPs-labelled test strips.ST specificity was analyzed in accordance with agarose gel outputs of polymerase chain reaction(PCR)and SD-LAMP.We detected ST in foods with an acceptable recovery of 85%–110%.The method is rapid,simple,almost equipment-free,and suitable for bacterial detection in foods and for clinical diagnosis.展开更多
The isolation and culture of conventional detection method of salmonella can not meet the testing requirements of quick and easy detection at the grassroots level. In this study, we prepare the fluorescent nanoparticl...The isolation and culture of conventional detection method of salmonella can not meet the testing requirements of quick and easy detection at the grassroots level. In this study, we prepare the fluorescent nanoparticles as a marker, covalently conjugate with monoclonal antibodies of Salmonella pullorum. The whole Salmonella pullorum antigen and goat anti-mouse antibody sprayed on the nitrocellulose membranes are used as test line and control line. The fluorescence nanoparticles immune based lateral flow strips are made according to the principle of antigen-antibody immune response. The test strips may interpret results within 30 min. The results of the salmonella A, S. agona, S. chester and S. arechavaleta are positive, including, S. agona for weakly positive. After analysis, it is found that in addition to the salmonella of group A, the other positive salmonella are in group B. But it is negative of S. derby, S. rissen, and other 6 kinds of salmonella, with good specificity. The fluorescence nanoparticles immune based lateral flow strips are a little of sample can be detected fast, easily, inexpensive, easy to universal without professional technical personnel detection method. It provides a new detection method for the detections of Salmonella pullorum.展开更多
The sandwich-type lateral fl ow assays relying on dual aptamers with high sensitivity and specifi city have been broadly explored.However,it is unlikely to match a pair of specifi c aptamers that can bind a small mole...The sandwich-type lateral fl ow assays relying on dual aptamers with high sensitivity and specifi city have been broadly explored.However,it is unlikely to match a pair of specifi c aptamers that can bind a small molecular target(e.g.,cocaine)simultaneously due to the steric hindrance.In response,we herein introduced the strategy of“one divides into two”into the construction of sandwich-type lateral fl ow strip assay(LFSA).Specifi cally,we split a single cocaine-recognizing aptamer into two segments,either of which was conjugated with gold nanoparticles(AuNPs)or labeled with biotin,serving as signal probe and capture probe,respectively.Upon the presence of the target molecule,a ternary sandwich complex comprised of the two halves of the aptamer and the target formed.Such sandwich-type LFSA exhibited an excellent nonlinear logarithmic response in the range from 10μmol/L to 5 mmol/L with R^(2)=0.9994.The sensitive on-site detection of cocaine in artifi cial biological samples including urine and sweat was achieved within 15 min,with the visual limit of detection as low as 50μmol/L for urine and 200μmol/L for sweat,and the recovery rates of 83.6-107.4%.展开更多
Diseases caused by foodborne pathogens are one of the main burdens of public health and seriously hinder global social and economic development.In this research,a novel lateral flow strip was successfully constructed ...Diseases caused by foodborne pathogens are one of the main burdens of public health and seriously hinder global social and economic development.In this research,a novel lateral flow strip was successfully constructed for the simultaneous detection of Gram-positive and Gram-negative bacteria based on the fluidity and color aggregation effect of Au nanoparticles(AuNPs).The lateral flow strip first combined ampicillin(AMP)antigens with AuNPs to form AuNPs-AMP antigens as the first recognition molecule.Then vancomycin specifically recognizing Gram-positive bacteria,and aptamers specifi-cally recognizing Gram-negative bacteria were used as the second recognition molecules.Finally,Gram-positive bacteria and Gram-negative bacteria were detected rapidly using this sandwich mode.The strip can rapidly test the samples within 5 min.Using a lateral flow strip detector,the limit of detection was 4 CFU/mL,and the recovery rates in honey samples were 78.2-88.6%.The lateral flow strip constructed can detect foodborne pathogens quickly,accurately and e fficiently,which is of great significance for food safety detection.展开更多
In this work,a novel conjugate of ractopamine and bovine serum albumin(RAC–BSA)has been developed via the Mannich reaction,with a mole coupling ratio for RAC–BSA of 9:1.The proposed conjugation method provides a sim...In this work,a novel conjugate of ractopamine and bovine serum albumin(RAC–BSA)has been developed via the Mannich reaction,with a mole coupling ratio for RAC–BSA of 9:1.The proposed conjugation method provides a simple and one-step method with the use of fewer reagents compared with other conjugation methods for competitive immunoassays.RAC–BSA conjugation was used to fabricate a competitive lateral flow strip test for RAC detection in animal feed.For sample preparation,RAC was spiked in swine feed purchased from the local markets in Thailand,and methanol and running buffer at a volume ratio of 10:90 was used as extraction buffer.The procedures for sample preparation were completed within 25 min.Under optimal conditions,the limit of detection(LOD),assessed by the naked eye within 5 min,was found to be 1 ng/g.A semi-quantitative analysis was also conducted using a smart phone and computer software,with a linearity of 0.075–0.750 ng/g,calculated LOD of 0.10 ng/g,calculated limit of quantitation of 0.33 ng/g,and good correlation of 0.992.The recoveries were found in the range of 96.4%–103.7%with a relative standard deviation of 2.5%–3.6%for intra-and inter-assays.Comparison of the results obtained by the strip test with those obtained by enzyme-linked immunosorbent assay had a good agreement in terms of accuracy.Furthermore,this strip test exhibited highly specific RAC detection without cross reactivity with related compounds.Therefore,the RAC–BSA conjugation via the Mannich reaction can be accepted as a one-step and easy conjugation method and applied to the competitive lateral flow strip test.展开更多
基金the National Natural Science Foundation of China(Grants No.21475030,21804028)the Fundamental Research Fund for central university(Grants No.2017HGPA0162,JZ2018HGTA0205,PA2017GDQT0018)+2 种基金the grant of 2017YFF0208600,the China Agriculture Research System-48(CARS-48)Anhui Provincial Modern Argo-industry Tech.Research System(NYCYTX-2016-84)the S&T Research Project of Anhui Province(Grant No.15czz03109).
文摘In order to enhance the flavor of chafing dish and increase the attraction of consumers,the poppy shell is reported to be illegally added to the condiments of chafing dish.In this research,a rapid,simple,and convenient method based on the classic immunochromatographic lateral flow strip(LFS)with gold nanoparticles(GNPs)labeling was developed for easy monitoring of morphine(MOP),an effective component of poppy shell.Under optimized conditions,this developed LFS can well realize the detection of target MOP in the condiments of chafing dish in less than 10 min without any complicated pre-treatments.The limit of detection(LOD)can be achieved as low as 0.1 ppb for standard MOP or the MOP spiked condiments of chafing dish.All these results of the research strongly demonstrate that this established LFS method can be successfully applied in practical rapid and accurate on-site screening of poppy shell in condiments of chafing dish.
基金This work was supported by the National Key Research and Development Program of China(2019YFC1606300)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01S174)the Guangdong Academy of Sciences Special Project of Implementing Innovation-Driven Development Capacity Building(2018GDASCX-0401).
文摘Rapid,sensitive,point-of-care detection of pathogenic bacteria is important for food safety.In this study,we developed a novel quantum dot nanobeads-labelled lateral flow immunoassay strip(QBs-labelled LFIAS)combined with strand displacement loop-mediated isothermal amplification(SD-LAMP)for quantitative Salmonella Typhimurium(ST)detection.Quantum dot nanobeads(QBs)served as fluorescence reporters,providing good detection efficiency.The customizable strand displacement(SD)probe was used in LAMP to improve the specificity of the method and prevent by-product capture.Detection was based on a sandwich immunoassay.A fluorescence strip reader measured the fluorescence intensity(FI)of the test(T)line and control(C)line.The linear detection range of the strip was 10^(2)–10^(8) colony forming units(CFU)·mL^(-1).The visual limit of detection was 10^(3) CFU·mL^(-1),indicating that the system was ten-fold more sensitive than AuNPs-labelled test strips.ST specificity was analyzed in accordance with agarose gel outputs of polymerase chain reaction(PCR)and SD-LAMP.We detected ST in foods with an acceptable recovery of 85%–110%.The method is rapid,simple,almost equipment-free,and suitable for bacterial detection in foods and for clinical diagnosis.
文摘The isolation and culture of conventional detection method of salmonella can not meet the testing requirements of quick and easy detection at the grassroots level. In this study, we prepare the fluorescent nanoparticles as a marker, covalently conjugate with monoclonal antibodies of Salmonella pullorum. The whole Salmonella pullorum antigen and goat anti-mouse antibody sprayed on the nitrocellulose membranes are used as test line and control line. The fluorescence nanoparticles immune based lateral flow strips are made according to the principle of antigen-antibody immune response. The test strips may interpret results within 30 min. The results of the salmonella A, S. agona, S. chester and S. arechavaleta are positive, including, S. agona for weakly positive. After analysis, it is found that in addition to the salmonella of group A, the other positive salmonella are in group B. But it is negative of S. derby, S. rissen, and other 6 kinds of salmonella, with good specificity. The fluorescence nanoparticles immune based lateral flow strips are a little of sample can be detected fast, easily, inexpensive, easy to universal without professional technical personnel detection method. It provides a new detection method for the detections of Salmonella pullorum.
基金supported by the National Natural Science Foundation of China(22090050,22122410,21874121)the National Key Research and Development Program of China(2018YFE0206900)+1 种基金Hubei Provincial Natural Science Foundation of China(2020CFA037)Zhejiang Provincial Natural Science Foundation of China(LD21B050001)
文摘The sandwich-type lateral fl ow assays relying on dual aptamers with high sensitivity and specifi city have been broadly explored.However,it is unlikely to match a pair of specifi c aptamers that can bind a small molecular target(e.g.,cocaine)simultaneously due to the steric hindrance.In response,we herein introduced the strategy of“one divides into two”into the construction of sandwich-type lateral fl ow strip assay(LFSA).Specifi cally,we split a single cocaine-recognizing aptamer into two segments,either of which was conjugated with gold nanoparticles(AuNPs)or labeled with biotin,serving as signal probe and capture probe,respectively.Upon the presence of the target molecule,a ternary sandwich complex comprised of the two halves of the aptamer and the target formed.Such sandwich-type LFSA exhibited an excellent nonlinear logarithmic response in the range from 10μmol/L to 5 mmol/L with R^(2)=0.9994.The sensitive on-site detection of cocaine in artifi cial biological samples including urine and sweat was achieved within 15 min,with the visual limit of detection as low as 50μmol/L for urine and 200μmol/L for sweat,and the recovery rates of 83.6-107.4%.
基金supported by the Breeding Plan of Shandong Provincial Qingchuang Research Team(2019-135)Qingdao Science and Technology Fund(21-1-4-sf-6-nsh)+1 种基金Postgraduate Innovation Program of Qingdao Agricultural University(QNYCX20028)High-level Talent Start-up fund from Qingdao Agricultural University(663/1121045)
文摘Diseases caused by foodborne pathogens are one of the main burdens of public health and seriously hinder global social and economic development.In this research,a novel lateral flow strip was successfully constructed for the simultaneous detection of Gram-positive and Gram-negative bacteria based on the fluidity and color aggregation effect of Au nanoparticles(AuNPs).The lateral flow strip first combined ampicillin(AMP)antigens with AuNPs to form AuNPs-AMP antigens as the first recognition molecule.Then vancomycin specifically recognizing Gram-positive bacteria,and aptamers specifi-cally recognizing Gram-negative bacteria were used as the second recognition molecules.Finally,Gram-positive bacteria and Gram-negative bacteria were detected rapidly using this sandwich mode.The strip can rapidly test the samples within 5 min.Using a lateral flow strip detector,the limit of detection was 4 CFU/mL,and the recovery rates in honey samples were 78.2-88.6%.The lateral flow strip constructed can detect foodborne pathogens quickly,accurately and e fficiently,which is of great significance for food safety detection.
基金Project Project supported by the Thailand Research Fund through the International Research Network(No.PHD58W0001)the Thailand Research Fund through Research Team Promotion Grant the Ratchadaphisaksomphot Endowment Fund of Chulalongkorn University(No.RTA6080002),Thailand
文摘In this work,a novel conjugate of ractopamine and bovine serum albumin(RAC–BSA)has been developed via the Mannich reaction,with a mole coupling ratio for RAC–BSA of 9:1.The proposed conjugation method provides a simple and one-step method with the use of fewer reagents compared with other conjugation methods for competitive immunoassays.RAC–BSA conjugation was used to fabricate a competitive lateral flow strip test for RAC detection in animal feed.For sample preparation,RAC was spiked in swine feed purchased from the local markets in Thailand,and methanol and running buffer at a volume ratio of 10:90 was used as extraction buffer.The procedures for sample preparation were completed within 25 min.Under optimal conditions,the limit of detection(LOD),assessed by the naked eye within 5 min,was found to be 1 ng/g.A semi-quantitative analysis was also conducted using a smart phone and computer software,with a linearity of 0.075–0.750 ng/g,calculated LOD of 0.10 ng/g,calculated limit of quantitation of 0.33 ng/g,and good correlation of 0.992.The recoveries were found in the range of 96.4%–103.7%with a relative standard deviation of 2.5%–3.6%for intra-and inter-assays.Comparison of the results obtained by the strip test with those obtained by enzyme-linked immunosorbent assay had a good agreement in terms of accuracy.Furthermore,this strip test exhibited highly specific RAC detection without cross reactivity with related compounds.Therefore,the RAC–BSA conjugation via the Mannich reaction can be accepted as a one-step and easy conjugation method and applied to the competitive lateral flow strip test.
