The Study Of Antibiotie Residues Detection Methods Based On Aptasensor

In this study, the new research progress on aptasensor has been reviewedbriefly, and took use of self-assembly and covalent bonding technology toconstruct aptasensor for kanamycin detection. The nanocomposites such asnanogold, multi-walled carbon, chitosan, graphene were used to improve theperformance of the aptasensor. The kanamycin aptamers can specific binding tokanamycin to more effectively complete the rapid detection of target componentskanamycin.The research work of this paper mainly in the following aspects:1. Aptasensor based on thionine, graphene-polyaniline composite film andgold nanoparticles for kanamycin detection in milk.An electrochemical aptasensor was developed for the detection of kanamycinbased on the synergistic contributions of thionine (TH), graphene-polyanilinecomposite film (Gr-PANI) and gold nanoparticles (GNPs) nanocomposites. TH hasexcellent electrocatalytic activity toward the redox of small molecular compounds.Owing to Gr-PANI composite have the amino and carboxyl groups, it haveenhanced electron transfer between work electrode surface and potassiumferricyanide. Gold nanoparticles acted as the transducer between the aptamer andGr-PANI composites. By cyclic voltammetry (CV) and electrochemical differentialpulse voltammetry (DPV) to characterize the aptasensor assembly process. Byscanning electron microscopy (SEM) to characterize the morphologies of thenanocomposites. The experimental conditions such as the concentration of aptamer,the natural drying time of aptamers and the pH of test solution were optimized.Based on the above optimum conditions, this aptasensor showed a favorableanalytical performance for kanamycin detection with a detection limit of8.6×10-9M.2. Aptasensor based on chitosan-gold nanoparticles, graphene-goldnanoparticles and multi-walled carbon nanotubes-cobalt phthalocyaninenanocomposites for kanamycin detection in milk.An electrochemical aptasensor was developed for the detection of kanamycin based on the synergistic contributions of chitosan-gold nanoparticles (CTS-GNPs),graphene-gold nanoparticles (GR-GNPs) and multi-walled carbonnanotubes-cobalt phthalocyanine (MWCNTs-CoPc) nanocomposites. CTS-GNPs,GR-GNPs and MWCNTs-CoPc as nanocomposites mediator improved electronrelay during entire electron transfer process, made enzyme keep a high activity,and improved the aptasensor response speed. The modified processes of theaptasensor was characterized by cyclic voltammetry (CV), and the morphologiesof the nanocomposites were characterized by scanning electron microscopy (SEM).The experimental conditions such as the concentration of aptamer, the naturaldrying time of aptamers and the pH of test solution were optimized. Based on theabove optimum conditions, this proposed aptasensor displayed high sensitivity,highly specific, low detection limit (5.8×10-9M)(S/N=3) and excellent stability. Itwas successfully applied to the detection of kanamycin in real milk spikedsamples.