Non-Enzymatic Electrochemical Sensing Fabrics And Wearable Applications Based On Conductive MOF

Along with the increase of people’s health awareness,flexible wearable sensors for human health monitoring are gaining more and more attention.Wearable sensors can convert non-electrical signals such as electricity,light,temperature,chemical action,etc.into electrical signals.It usually includes components such as detection components,conversion components,control circuits,and signal conversion circuits.Wearable sensors can be broadly classified into three types:wearable physical sensors,wearable chemical sensors,and wearable biosensors.Industry insiders believe that wearable sensors have great potential for applications in medical,sports,and military fields.When electrochemical biosensors are used for real-time monitoring of body fluids,skin contact helps collect,analyze and transfer sweat,tears,saliva and other body fluids to provide real-time information about sweat p H and blood glucose,lactate,metal ion salts,heavy metals and more.Body fluid information plays an important role in real-time monitoring of individual vital signs and disease diagnosis.However,little research has focused on the safety and comfort of human skin.Therefore,it has become an urgent issue to create a wearable sensor that can balance sensitivity and wearing comfort.Metal organic framework（MOF）is a porous material with diverse structure and easy modification.With their high void fraction and large surface area,MOF materials have promising applications in catalysis,separation,sensors,and gas adsorption.Based on this,this paper prepares flexible electrochemical sensors from the preparation of MOF.The bimetallic Ni Co-MOF was used as the electrode modification material and ethylene-vinyl acetate copolymer as the adhesion material to construct a three-dimensional multilayer flexible fabric-based electrochemical sweat sensor.Details are as follows.Preparation of monometallic ionic Ni-MOF:Monometallic Ni-MOF was prepared in a solvothermal reaction to combine nickel nitrate precursor with terephthalic acid（H₂BDC）ligand using polyvinylpyrrolidone（PVP）and acetonitrile as the shape guide.The layered sheet Ni-MOF exhibited excellent glucose electrocatalytic oxidation properties,and the sensitivity of the layered sheet Ni-MOF electrode modification material was 0.884μA·m M^-1 with a limit of detection（Lo D）of 2.647 m M（S/N=3）.Preparation of bimetallic ionic Ni Co-MOF:The bimetallic Ni Co-MOF was prepared by the one-pot method,and the glucose catalytic oxidation performance of the monometallic ionic MOF and bimetallic ionic MOF was compared.Due to the synergistic effect of Ni ions and Co ions,the bimetallic ion MOF showed better glucose electrocatalytic oxidation performance and long-term stability than the monometallic ion MOF.The sensitivity of Ni Co-MOF electrode modification material was 1.293μA·m M^-1 and the limit of detection（Lo D）was 1.522 m M（S/N=3）.Finally,Ni Co-MOF was selected as the electrode modification material and was directly drop-coated on the working electrode for sweat monitoring.Selection of fabric substrate and construction of multilayer electrochemical sensing fabric:three electrodes were fabricated on the fabric substrate using screen printing method.The electrode modification material was loaded onto the working electrode using drop coating method,and the practicality（including washing resistance and bio-cytocompatibility）and wearing comfort of the substrate after loading MOF on various types of fabrics were compared.The effects of different levels of MOF electrode modification materials on the electrochemical performance of the flexible sensor were investigated,and the glucose standard curve of the flexible sweat sensor was determined at the optimal MOF content.Finally,a multilayer fabric device consisting of a moisture-absorbing layer（polypropylene）,a detection layer（nylon）,and a hydrophobic layer（polyester）was formed.The sensitivity of this multilayer fabric device was 2.935μA·m M^-1,and the detection limit was 1.686 m M（S/N=3）.This provides a new way to prepare flexible wearable sensor development.