Based On Graphene Nanomaterials Research Of Bisphenol A Sensor

With the remarkable development of industry, more and moreharmful chemical substances are discharged into the environment.Some of these environmental chemicals have pernicious influence onthe normal homeostasis, reproduction, growth of biological organismsbecause these chemicals can imitate, obstruct, alter, or interfere withthe endogenous estrogen in organism, resulting in the contamination ofwater, atmosphere, soil, plants, and sediment, even harm for humanbeings and animals. These deleterious chemicals are known asenvironmental estrogens or endocrine-disrupting chemicals (EDCs). Thepotential sources of EDCs pollutions are originated from the petroleum,electronic products, plastics, paints, pesticides and some foods. Theycan be enriched through food chain and concentrated bybioaccumulation in human body. The EDCs are difficult to bedecomposed and degraded, so they are not easy to excrete. AlthoughEDCs now exist at an extremely low level, they have a great impact onhuman body because EDCs will cause the disorders of the endocrinesystem, the transmission block of nervous system, the affection ofenzyme system, the reduction of immunologic function and themalformation or cancerization of organs.Bisphenol A (BPA),2,2-bis (4-hydroxyphenol) propane, is one of theEDCs. It is a major raw material in the manufacture of epoxy resins andpolycarbonates, and also widely used in the production of finechemicals, pesticide, paint, heat stabilizer and so on. It has beenreported that BPA has been detected from water, atmosphere,sewage effluents, soil and foods. Some daily necessities and industrialproducts closely related to human life also contains BPA, such asbeverage bottles, milk bottles, medical apparatus and instruments,water pipes and food packaging. Thus, the determination of BPA is crucial for human health.Graphene is a two-dimensional material comprised of one atomthick planar layer. Their bonds formed between sp2hybridized carbonatoms which are packed in honeycomb crystal lattice are hard to bebroken. Due to its special structure, graphene possesses severalextraordinary physical and chemical properties, such as strongmechanical strength, excellent conductivity, large surface area, highelectrocatalytic activities and good biocompatibility.In this paper, we prepared the electrochemical sensors for thedetermination of BPA with the combination of graphene andlayer-by-layer self-assembly technique. The research ideas wereoutlined as follows:(1) graphene was used as the carrier of tyrosinasedue to its extraordinary electron transfer property and biocompatibility,and then the electrochemical biosensors were fabricated with highsensitivity, good reproducibility and stability;(2) the electrochemicalsensor for the determinatiuon of BPA was prepared based on thepremium properties of graphene and other nanomaterials.The detailed materials including three major components aresummarized as follows:1A Novel Biosensor Based on Multi-Layers Modified Glassy CarbonElectrode for Determination of Bisphenol AA novel biosensor based on Prussian Blue (PB), graphene, hollowgold anopheles (HGNs) and tyrosinase (Tyr) for the determination of BPAwas prepared. The hollow gold nanoparticles (HGNs) werecharacterized by transmission electron microscopy. Cyclic voltammetryand electrochemical impedance spectroscopy experiments werecarried out to investigate the electrochemical properties of themodified electrode. The sensor exhibits good amperometric responsetowards bisphenol A (BPA) due to the excellent biological conductivityand biocompatibility of graphene and HGNs. Under the optimal experimental conditions, the current is linear with the concentration ofBPA in the range from1.000×10-7to7.850×10-6M, with a detectionlimit of5.200×10-8M (S/N=3) and a correlation coefficient of0.997.The biosensor showed good performance in reproducibility, stabilityand interference experiments.2Bisphenol A Sensor Based on Au Nanoparticles,Graphene/Chitosan/Ionic Liquid Composite and L-cysteine CappedQuantum DotsA bisphenol A electrochemical sensor was fabricated byimmobilizing Au nanoparticles, graphene/chitosan/ionic liquidcomposite and L-cysteine capped quantum dots on the surface ofglassy carbon electrode. The electrochemical behavior of the BPAsensor was investigated by cyclic voltammetry and electrochemicalimpedance spectroscopy. The sensor exhibits good amperometricresponse towards bisphenol A (BPA) because of the excellentconductivity of graphene and ionic liquid. Under the optimalexperimental conditions, the current is linear with the concentration ofBPA in the range from5.000×10-8to7.050×10-6M, with a detectionlimit of2.000×10-8M (S/N=3) and a correlation coefficient of0.999.3Bisphenol A Biosensor Based on Glassy Carbon Electrode Modifiedwith Ag Nanoparticles, Graphene, Tyrosinase and PolyamidoamineA bisphenol A biosensor based on Ag nanoparticles, graphene,tyrosinase and polyamidoamine (PAMAM) modified electrode wasprepared. The electrochemical behavior of the BPA biosensor wasinvestigated by cyclic voltammetry and electrochemical impedancespectroscopy. Owning to the special physicochemical characters ofthe nanomaterials, the high reactivity of Ag nanoparticles andelectrostatic interaction between PAMAM and BPA, the sensor exhibitsgood amperometric response towards BPA. Under the optimalexperimental conditions, the current is linear with the concentration of BPA in the range from1.000×10-7to3.335×10-5M, with a detectionlimit of3.000×10-8M (S/N=3) and a correlation coefficient of0.998.