The Fabrication Of Noval Electrochemical Aptasensor Based On Carbon Nanocomposites For The Detection Of Antibiotic

Antibiotics are widely used in the treatment of human and animal diseases and they also have been used as growth promoters in the field of animal husbandry.The improper and excessive use of antibiotics will cause residues in the ecosystem and animal derived food.Because of their threat to public health and ecological system,antibiotic residue problem has attracted more and more wide attention.Therefore,the development of efficient and sensitive methods to detect antibiotic is very necessary.In this paper,the advanced nanotechnology and aptasensor technology was combined and three kinds of high performance electrochemical aptasensor was prepared.They are implemented separately to detect penicillin,ampicillin and chloramphenicol efficiently and sensitively.Some researches were made as follows:1.PEDOT-AuNPs/GR-Fe₃O₄ NPs composite based electrochemical aptasensor for the detection of penicillin: A novel electrochemical aptasensor was developed for sensitive detection of penicillin antibiotic,which used penicillin aptamer as specific recognition element and used a novel composite film consisting of magnetic graphene nanocomposite?GR-Fe₃O₄NPs?and poly?3,4-ethylenedioxythiophene?-gold nanoparticles?PEDOT-AuNPs?composite as platform.The structures of GR-Fe₃O₄ NPs and PEDOT-AuNPs composite have been investigated by scanning electron microscopy?SEM?.Cyclic voltammetry?CV?,electrochemical impedance spectroscopy?EIS?and differential pulse voltammetry?DPV?were used to demonstrate the electrochemical performances of the as-prepared aptasensor.Under the optimized conditions,the proposed aptasensor exhibited high sensitivity for the detection of penicillin with a wide linear range from 0.1 to 200 ng/mL and a low detection limit of 0.057 ng/mL.The proposed aptasensor also showed good stability,satisfactory reproducibility and high specificity.2.AuNPs@MGR/PEDOT-AuNPs composite based electrochemical aptasensor for the detection of ampicillin: A novel aptamer-based electrochemical biosensor was prepared for highly sensitive detection of ampicillin based on PEDOT-AuNPs and multifunctional graphene composite?AuNPs@MGR?and ampicillin aptamer was used as specific recognition element.The structures of composites have been investigated by SEM.CV and DPV wereused to demonstrate the electrochemical performances of the as-prepared aptasensor.Under the optimal conditions,the aptasensor exhibited a good linear response to ampicillin in range from 0.1 ng/mL to 200 ng/mL and a lower detection limit of 0.041 ng/mL?S/N=3?.The proposed aptasensor also showed a high sensitivity,good stability and excellent selectivity to ampicillin.3.AuNPs/MWCNTs-Fe₃O₄NPs/CNS composite based electrochemical aptasensor for the detection of chloramphenico?CAP?: An excellent electrochemical aptasensor using CAP aptamer as specific recognition element and based on carbon nanosphere?CNS?,magnetic multi-walled carbon nanotubes nanocomposite?MWCNTs-Fe₃O₄NPs?,gold nanoparticles?AuNPs?was employed for sensitive and selective detection of CAP.The structures of composites have been investigated by SEM and TEM.CV and DPV were used to demonstrate the electrochemical performances of the as-prepared aptasensor.Under the optimal conditions,The proposed aptasensor exhibited a wide linear range for CAP from 0.05 to 100 ng/mL with a detection limit of 0.021 ng/m L.The designed aptasensor showed an excellent analytical performance with good reproducibility,high selectivity and stability.Furthermore,all of the proposed aptasensor have been successfully applied to analyze target materials from the real samples and yielded satisfactory results.