Fabrication And Application Of Fully Printed Flexible Electrochemical Sensor

Flexible electronics have been widely used in the medical field due to their unique advantages of good mechanical matching with organisms.Among them,flexible electrochemical sensors are an important development direction.Ink-jet printing is a new micro-machining method,which has the characteristics of no template,low cost,high precision,strong flexibility and so on.Ink-jet printing is widely used in the manufacturing of flexible electronics.Therefore,this paper developed a flexible electrochemical biosensor based on inkjet printing technology,and applied it to the detection of glucose and lactic acid.In this paper,the applications of flexible electronics,especially wearable flexible electrochemical sensors in the medical field are introducted.There are two problems（preparation of electrode ink and preparation of active material ink for electrochemical sensing）around the construction of flexible electrochemical sensors need to be solved,and the analysis and research about them are carried out in this paper.The main research content is as follows:Firstly,the gold nano ink was prepared.Considering the electrical conductivity and biocompatibility,a kind of gold nanoparticle with a diameter of about 5 nm was prepared by using L-cysteine as stabilizer.The gold nanoparticle ink was dispersed with glycol and water as the mixed solvent.The obtained gold nanoparticle ink had good dispersibility and could be used for inkjet printing electrode.Secondly,flexible substrate was selected.In this paper,the contact angles of gold nanoink on different substrates were tested,and polyethylene terephthalate（PET）sheet was selected as the substrate for the construction of flexible electrochemical biosensor.Thirdly,active materials for electrochemical sensing were synthesized.A kind of conductive polymer and metal composite core-shell nanoparticle（Au-Pd@PIn-6-NH₂）was synthesized by"one-pot method",and it was applied to the detection of hydrogen peroxide.Then the amino group in poly（6-amino）indole was used as the active site to immobilize glucose oxidase and lactic acid oxidase by glutaraldehyde,and they were applied to the detection of glucose and lactic acid.Fourthly,the construction and application of flexible electrochemical sensor.Gold electrodes were printed on a PET sheet using a synthetic gold nano ink.A layer of silver was then printed on one of the gold electrodes and chlorinated to serve as a reference electrode.Finally,the prepared enzyme solution was printed on one of the gold electrodes as an enzyme sensing layer,which was applied to the detection of glucose and lactic acid standard solutions.This paper also proves that the biocompatibility of Au-Pd@PIn-6-NH₂ material and flexible electrochemical sensor is good,which provides a new choice for the development of wearable sweat sensor.