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Lateral flow chromatography is a new rapid detection and sensing technology,has the advantages of low cost,convenient to use and rapid detection.This method can better meet the requirements of quality and safety surveillance and on-site rapid screening by comparing with the physical and chemical detection methods which are expensive,complicated to operate and require high detection environment.In this paper,the lateral flow chromatography strips were introduced including the test methods,the classification of marking materials and their practical applications in various fields.The researches on the application of lateral flow chromatography strips in biological and food safety testing was reviewed including the advantages and the current research status.The existing bottlenecks and the future development direction were also analyzed.These can provide insight for the further application and in-depth research of strip rapid detection technologies.
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The rapid detection technology in food safety plays a vital role in the field of preventive medicine.The traditional physical and chemical detection methods have some limitations,such as costly,difficult to operate and high requirements on environment,can not meet the needs of quality and safety on-site rapid screening,and are gradually replaced by emerging sensor detection technologies.The aptamer-upconversion biosensor technology is a novel rapid detection technology,which is based on the combination of functionalized upconversion nanomaterials and aptamer technology.Compared with the traditional immunofluorescence technology,it has advantages in sensitivity,specificity and stability,and is widely used in rapid detection.In this paper,the upconversion luminescence and aptamer technologies were briefly introduced,and the aptamer-based upconverting phosphor biosensing technology and its application in rapid detection of food safety were summarized.Based on the current research status,the bottleneck and the future development trend of this technology were analyzed,which provides a reference for the application of this technology in food safety and other fields.
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Surface plasmon resonance (SPR) sensor technology,with its features of real-time,fast,no need for labeling,no background interference and non-destructive to samples,etc.,has been widely used in the field of biotechnology,medicine,environmental science and drug detection.This article gives an overview of the recent popular studies and their progress in SPR technology is reviewed,especially giving a detailed overview of the surface modification technique,related hyphenated techniques and application of SPR in clinical examination.Hyphenated techniques is discussed from three aspects of molecular imprinting technique,SPR based immunoassay and nucleic acids SPR biosensor as well.
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<p><b>OBJECTIVE</b>To develop a quartz crystal microbalance (QCM) immunosensor with high sensitivity and selectivity for the rapid detection of diethylstilbestrol.</p><p><b>METHODS</b>Dextran was used as reducing agent for preparing gold nanoparticles (AuNPs) with the size of 40 nm. The AuNPs were coupled with anti-DES antibody after amination. A monolayer was generated after immersing the quartz crystal into the solution of 5 mmol/L 11-mercaptoundecanoic acid(MUA) for 16 hours. After the monolayer was activated by 1-ethyl-3-(3-dimethylaminopropry) carbodiimide hydrochloride (EDC·HCl) and N-hydrosuccinimide (NHS), 20 μl of 2.2 mg/ml DES-HS-BSA was dropped onto the surface of crystal to prepare a sensitive membrane which can recognize DES specifically. Then, 50 μl of 1 mol/L ethanolamine (pH 8.5) was used to seal the carboxylic groups to make the sensitive membrane which could identify DES specifically. QCM immunosensor was used as detection platform to optimize the reaction conditions. Under the optimized conditions, 10 μl of 28 μg/ml AuNPs-antibody was mixed with 10 μl of 0.03-2.5 μg/ml DES, and the mixture was added on the sensitive membrane. QCM immunosensor was used to detect the signals and the standard curve was obtained at the same time. The detection limit was calculated based on the standard curve. The specificity was evaluated by testing DES and its analogues with the same concentration.</p><p><b>RESULTS</b>The optimized concentration for the immobilization of DES-HS-BSA on the surface of QCM was 2.2 mg/ml. The optimized concentration for coupling anti-DES antibody with AuNPs was 7 μg/ml and 15 nmol/L, respectively. The optimized concentration of AuNPs-antibody was 14 μg/ml. The logarithm of DES concentration was proportional to the frequency shift in the range of 0.16-500 ng/ml, Δf=-24.170 lgCDES+69.71, R(2)=0.998. The detection limit of this method was 0.13 ng/ml. DES analogues could not influence the detection of DES obviously, so the sensor had good specificity.</p><p><b>CONCLUSION</b>The quartz crystal microbalance immunosensor with gold nanoparticals amplification could detect DES sensitively and rapidly.</p>
Subject(s)
Biosensing Techniques , Diethylstilbestrol , Gold , Limit of Detection , Nanoparticles , Quartz Crystal Microbalance TechniquesABSTRACT
To develop a low-cost, reliable, easy-to-maintain and practical instrument for protein purification. Some ultraviolet luminescent diode was used to provide 280 nm light source, and high-sensitivity S1336 photo-electric detector was employed for real-time monitoring of purified protein solution flowing through quartz cell to supervise the concentration of the protein. The instrument gave voice alarm and stopped working in case the protein concentration was less than the standard one. The lower SCM monitored the liquid level of the protein collecting cup and the position of loading arm through laser infrared distance sensor, so that a cup full of protein might be replaced by another empty cup. The instrument involved in Samsung S5PV210 embedded master computer, Wince6.0 operating system, Keil4.0 and VS2005. Trials proved that the instrument could perform real-time monitoring and curve display of dual-channel ultraviolet absorption, and could realize auto collection of 735 ml protein solution and up to 5-hour standby. The instrument developed has simple structure, high reliability and easy maintenance, and meets the desired require-ments.
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Surface plasmon resonance (SPR) sensing technology is a high-tech optical detection technolo-gy developed quickly in recent years, which combines biology, polymer chemistry and sensing technologies to form a rapid, sensitive, specific, portable and easy to operate detection technology. This paper outlines the mech-anism of SPR sensing technology for detection of low molecular weight analytes, the main application methods and research progress, discusses the advantages and shortages of the method, and foretastes the development prospect of this technology.
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A novel suspension array technology was established for the detection of three kinds of veterinary drug residues: chloramphenicol, clenbuterol and 17-β-estradiol. The three conjugates in which veterinary drugs coupled with BSA were immobilized on the solid carrier of the suspension microarray-polystyrene fluorescent microspheres/beads as detective probes. Indirect competitive technology was employed. Competitive reactions between the veterinary drugs in the aqueous phase and the veterinary drugs-BSA conjugates on the beads for coupling with their complimentary specific biotinylated monoclonal antibodies were carried out. And then, straptavidin-phycoerythrin was added for coupling and the fluorescent signals were captured. Afterwards the detective standard curves were plotted. The regular ELISA standard curves of the three veterinary drugs were also plotted. Comparison between suspension array and regular enzymE-linked immunosorbent assay(ELISA) was in the respects of the detective technology, the detection limits, the detective ranges, the samples detection and the multi-analysis. Suspension array technology is distinct advantageous except for specificity. There was well consistent performance between the two methods. The high-throughput suspension array provides a novel method for multi-analysis of veterinary drugs with simple operation, sensitive, rapid and low costing.
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<p><b>OBJECTIVE</b>To obtain geranylgeranyl diphosphate synthase gene of Salvia miltiorrhiza, and conduct bioinformatic and transcript expression analysis of the cloned SmGGPS1 gene.</p><p><b>METHOD</b>The degenerate primers were designed based on the conservative regions of GGPS protein sequences from public databases. The target gene was obtained from root of S. miltiorrhiza by use of homologous cDNA amplification and RACE technologies. The sequence alignment was performed using BLAST. The open reading frame was identified by use of the ORF Finder. The protein domains were defined by use of Prosite software and the signal peptide sequence was predicted by Target P1.1. MEGA4.0 was used to conduct multiple amino acid sequence alignment and construct the phylogenetic tree. Roots and leaves at the seedlings stage and roots, stems, leaves, buds and flowers in the flowering stage were sampled for transcript analysis. Semi-quantitative RT-PCR was used to detect the gene expression level. The complete gene of GGPS was obtained from S. miltiorrhiza genomic DNA by PCR using the cDNA-derived specific primer. The gene structure of GGPS was analyzed by comparison of the genomic DNA and its cDNA.</p><p><b>RESULT</b>The obtained 1 298 bp SmGGPS1 cDNA sequence contains an 1095 bp ORF, encoding 364 amino acids. It is predicted that it has a plastid targeting signal peptide of approximately 52 amino acid at the N-terminal end. It is to believe that this is the polyprenyl synthetase signature, and nucleic acid sequence comparison revealed that SmGGPS1 ORF has more than 60% identity to the reported GGPS. RT-PCR semi-quantitative analysis showed that the gene expresses in the all tested tissues, and with much higher level of expression in the leaves in the flowering stage. SmGGPS1 has a 397 bp intron.</p><p><b>CONCLUSION</b>For the first time the cloning of geranylgeranyl diphosphate synthase gene from S. miltiorrhiza was reported, and it provides a good basis for further functional study of SmGGPS1.</p>
Subject(s)
Amino Acid Sequence , Base Sequence , Cloning, Molecular , Farnesyltranstransferase , Chemistry , Genetics , Metabolism , Gene Expression Regulation, Enzymologic , Molecular Sequence Data , Open Reading Frames , Phylogeny , Plant Proteins , Genetics , Metabolism , Plants , Classification , Genetics , Salvia miltiorrhiza , Classification , GeneticsABSTRACT
Objective To study the effect of bisphenol A on the structure of the spleen and the expression of ER-? in F344 rats. Methods Fisher 344 rats were randomly divided into control,low-dose,moderate-dose and high-dose groups,10 in each and treated with bisphenol A through gavage at the doses of 4 mg/kg,40 mg/kg and 400 mg/kg respectively,once a day for 17 consecutive weeks. In the end of the experiment,the pathological examination of the spleen was done and the expression of ER-? was detected by western blotting. Results Compared with the control,the weight of high dose group decreased (P
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Objective:To conjugate nonylphenol and ovalbumin(OVA).Methods:Nonylphenol was conjugated to OVA by Mannich reaction with formaldehyde in phosphate buffer(PBS, pH=8.0).And we identified the conjugate by antichip and ultraviolet scan.Results:Nonylphenol was conjugated to OVA successfully, and nonylphenol monoantibody recognized the conjugate less than 2.68 ?g/ml.Conclusion:This is an easy method to produce the conjugate of nonylphenol successfully.