Studies Of Electrochemical Biosensors Based On Layered Double Hydroxide

Much attention has been devoted to the development of the electrochemical biosensor based on enzymes. It possesses important value in physic, environmental monitoring, food and military. Layered nanomaterials have many specialities, such as orderly structure, adjustable chemical composition, intercalationable, assembliable, and nanosheets obtained from the delamination of layered nanomaterials have a more open structure. Novel electrochemical biosensors have been fabricated based on these layered nanomaterials and nanosheets in this topic. It provides a new idea to develop new type of electrochemical biosensors, and it has broad application prospects.In this paper, the nanomaterials (layered double hydroxide compounds and exfoliated nanosheets) were used to immobilize Tyrosinase (Tyr) or Myoglobin (Mb) and investigate the electrochemical properties. The main contents of the thesis are given as follows:1. Mg-Al-Cl layered double hydroxide was applied to the immobilization of Tyr as a support matrix. Tyr almost retained bioactivity in the film. The electrochemical results revealed that it can be applied for determination of food preservative, benzoic acid.The detection of benzoic acid was performed via its inhibiting action on the Tyr/Mg-Al-Cl LDHs modified screen-print electrode. This inhibitor biosensor was successfully applied for the determination of benzoic acid in some real samples.2. Mb has been intercalated into Mg-Al-LDHNS by delamination and restacking through XRD analysis, and the direct electron transfer between the intercalated Mb and the underlying electrode was studied. Mb intercalated into Mg-Al-LDHNS retained its native secondary structure partly. The Mb-Mg-Al-LDHNS/GCE showed electrocatalytic activity in the reduction of H2O2.