In this work, a sea urchin gold nanoparticles-zearalenone aptamer- tetramethylrhodamine sensor was constructed. Sea urchin gold nanoparticles, prepared using the seed-mediated growth method, were used as Raman substrates. Nucleic acid aptamers were mainly used as specific recognition molecules.
View Article and Find Full Text PDFA nucleic acid aptamer based thermally oxidized porous silicon/zinc oxide microarray chip was constructed for the detection of ochratoxin A. The hybrid chains formed by aptamer and complementary chains labeled with fluorescent groups and fluorescent burst groups were used as recognition molecules, and the detection of toxins was accomplished on the chip by the principle of fluorescence signal burst and recovery. The modified QuEChERS method was used for sample pretreatment and the performance of the method was evaluated.
View Article and Find Full Text PDFA microfluidic paper chip colorimetric detection system based on surface molecular imprinting of zinc ferrite nanoparticles was established, and the detection images were obtained by smartphone for gray value analysis and determination of butachlor. The best functional monomers and addition ratio were selected by quantum chemical simulation calculation, the properties of the prepared molecularly imprinted polymers were analyzed, and the detection conditions were optimized. The linear range, sensitivity, and selectivity of the method were evaluated.
View Article and Find Full Text PDFA simple, fast, low cost, sensitive, intuitive, visual, label-free, and smartphone-assisted aptamer sensor based on colorimetric assay for the measurement of zearalenone was constructed. The nucleic acid aptamer of zearalenone was used as the recognition element and gold nanoparticles were used as the indicator. Several factors that could influence sensitivity, including the concentration of aptamer and NaCl, and incubation time, and specificity, have been investigated.
View Article and Find Full Text PDFA simple, rapid, low-cost, sensitive, intuitive, visual, label-free, colorimetric smartphone-assisted assay was developed for the measurement of aflatoxin B1 in miscellaneous beans. Ten different kinds of miscellaneous beans were treated and measured by modified QuEChERS(Quick、Easy、Cheap、Effective、Rugged、Safe) method with aflatoxin B1 nucleic acid aptamer as a recognition element and gold nanoparticles as indicators. Several factors influencing its sensitivity were investigated, including consumes and NaCl concentrations, as well as incubation time and specificity.
View Article and Find Full Text PDFA highly sensitive fluorescent sensing system of novel carbon quantum dots nano-fluorescent probe based on corn stalks was established for the determination of methyl parathion by alkaline catalytic hydrolysis and inner filter effect mechanism. The carbon quantum dots nano-fluorescent probe was prepared from corn stalks using an optimized one-step hydrothermal method. The detection mechanism of methyl parathion was revealed.
View Article and Find Full Text PDFOrganophosphorus pesticides will not only affect human health, but will also have serious impacts on the ecological environment. A simple, economical, safe, efficient, green and pollution-free and highly sensitive method was successfully established to analyze organophosphorus pesticides in different coarse cereals' samples. Under the optimal experimental conditions, the method was linear, the correlation coefficient are higher than 0.
View Article and Find Full Text PDFMetabolites of the Jinyu 88, Huanong 18, and Demeiya 9 maize varieties from the same origin were isolated and identified by GC-MS, and the specific metabolites and metabolic mechanisms of these three varieties of maize were preliminarily analysed and discussed. The metabolites were extracted with 80% methanol and derived with N,O-bis(trimethylsilyl)trifluoroacetamide. A total of 59 metabolites were identified.
View Article and Find Full Text PDFFood Addit Contam Part A Chem Anal Control Expo Risk Assess
November 2019
An extraction method based on metal-organic framework has been developed and applied to acetanilide herbicides, including metazachlor, propanil, pretilachlor, and butachlor, in black beans, red beans, and kidney beans. The acetanilide herbicides are extracted with a mixture of ethyl acetate and n-hexane. The extract solution is absorbed and purified with metal-organic framework MIL-101 (Zn).
View Article and Find Full Text PDFThe ultrasound-assisted ionic liquid foam flotation solid-phase extraction of sulfonylurea herbicides in milk was developed and validated. The proteins and lipids were isolated from the sample matrix by adding salt and adjusting the pH value. The target analytes eluted from the solid-phase extraction cartridge were determined by high-performance liquid chromatography.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
March 2014
The ionic liquid foam floatation solid phase extraction was established and applied to the extraction of six triazine herbicides, including desmetryn, secbumeton, terbumeton, terbuthylazine, dimethametryn and dipropetryn, in vegetable samples. To obtain the optimized experimental parameters, the effects of pH value of sample solution, the type and concentration of ionic liquid, the flow rate of carrier gas, foam floatation time, the type of solid phase extraction cartridge, the type and volume of elution solvent on the recoveries of the analytes were examined. The high performance liquid chromatography was applied to the determination of the analytes.
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