Phytic Acid-based Hydrogel Modified Electrode For The Detection Of Heavy Metals

Heavy metals are the main inorganic pollutants of water in global,unlike organic pollutants,heavy metals pollutants are non-biodegradable,even at low concentrations can cause irreversible damage to the organism.Therefore,the development of high accuracy and sensitivity of heavy metal ions detection method is one of the significant research topics in analytical chemistry field.Electrochemical detection method has been widely employed in heavy metal monitoring because of its simple operation,miniaturization and fast response.Electrochemical sensor ideal immobilized substrate should be porous,conductivity and stability.The development of an eco-friendly,biodegradable,fast adsorption efficiency and highly reusable adsorbent with fast adsorption efficiency is a necessary condition for effective remediation of toxic metal cationic wastewater.The stable structure of the hydrogel prevents the signal aggregation during the detection process,and its highly porous structure is not only beneficial to the immobilization of biomolecules and nanoparticles,but also to the target recognition and signal amplification.Thus,the hydrogel been widely concerned by researchers in the field of electrochemistry.In addition,some merits including good hydrophilicity and biocompatibility,excellent electrical conductivity and stability,and its reusability make hydrogels occupy a special position in the field of wastewater.Based on this,two kinds of polypropylene composite hydrogel materials based on phytic acid as cross-linking agent were designed and prepared,and successfully exploited in the analysis and detection of heavy metal ions in environmental sewage.The research content of this paper mainly includes the following two parts:（1）A 3D phytic acid cross-linked high-porous conductive hydrogel integrating g-C₃N₄for electrochemical multiplex sensing of heavy metal ionsThe phytic acid cross-linked high-porous conductive hydrogel was prepared with phytic acid as cross-linking agent and dopant,acrylamide as hydrogel matrix and aniline pyrrole copolymer as conductive polymer,and the g-C₃N₄nanosheets peeled by ultrasound were wrapped inside the hydrogel to further enhance the electrical conductivity and the adsorption capacity of heavy metal ion.The synthesized hydrogel has a highly porous three-dimensional network structure,excellent conductivity and stability.When it is used for Cd²⁺,Cu²⁺,Pb²⁺and Hg²⁺ion detection and analysis,the detection limits are 26.08 n M,53.23 n M,14.84 n M and 68.35 n M,respectively.Moreover,the sensor shows a high accuracy in lake water test.The preparation and application of the hydrogel in electrochemical sensor provided an available strategy to capture and detect the various heavy metal ion by electrochemistry in solution and has great commercial application prospect.（2）PAAM/PA/PDA conductive porous hydrogels doped with silver nanowires were prepared and used for rapid detection of lead ionsA rapid,sensitive and low pollution sensor,is used for direct detection of heavy metal ions in the wastewater is very ideal.In this chapter,a conductive porous polymer hydrogel-based electrochemical sensor was prepared for the detection of lead ions in environmental pollutants.The hydrogel was prepared mainly from phytic acid（PA）crosslinks polydopamine（PDA）and polyacrylamide（PAAM）by hydrogen bonds,and doped with silver nanowires.Combined with the selective adsorption capacity and good electrical conductivity of hydrogel,as an electrode modification material,the signal amplification and specific recognition can be obtained.Low detection limit and excellent stability proved potential application value of the platform,and widen the hydrogel materials applied in the analysis of the water environment.