Metal-Organic Frameworks Based Electrochemical Sensor For Detection Of Biomarkers

Metal-Organic Frameworks(MOFs)is a kind of functional material hybridized by a metal center and an organic ligand by means of coordination.In electrochemistry,MOFs with its excellent specific surface area,unique cavity structure,become the great potential of new multi-functional materials,can solve the problem of molecularly imprinted sensor preparation process,and can make use of MOFs characteristics of an electrical current or potential differences between enantiomers,be used to break up down the molecular membrane material.Due to the poor conductivity of MOFs materials,it is possible to construct suitable MOFs nanocomposites to solve this problem.The main work of this paper is to prepare a current electrochemical sensor based on MOFs-derived nanocomposites,a potential sensor based on the "differential potential ratio strategy" and an electrochemical paper-based sensor for glucose.Specific research includes the following contents:(1)A novel electrochemical sensor with high sensitivity and anti-interference was constructed by combining multi-wall carbon nanotubes(MWCNT)with zeolite imidazoles(ZIF-8)by a simple and efficient synthetic method.In the concentration range of 0.02 ?M~10.0 ?M,the peak oxidation current of dopamine DPV showed a good linear relationship with the increasing concentration,the detection limit was 3.5nM(S/N=3).Moreover,the constructed sensor also achieved satisfactory results in the detection of real complex samples with the recovery rate ranging from 95.0 % to109 %.It shows that the sensor has great potential in medical diagnosis.(2)The irregular chiral sea urchin-like MOF on the surface was immobilized to the surface of rGO in a simple way to form a two-layer composite sensing platform.After a series of condition optimization,the detection of L-/D-Trp has a significant potential difference(PD),and the maximum value can reach 98 mV.Different concentrations of tryptophan in proportion to the racemic mixture in the concentration range between 100 ?M to 1000 ?M successfully simulate a kind of potential "energy level" approach.Even in complicated cerebrospinal fluid,the ratio of L/D-tryptophan can be accurately detected.This method is expected to bring great potential for the stable chiral MOF and recognition of chiral molecules,providing a great applicationprospect in the field of pharmacological detection andclinical analysis.(3)Induced the Co-MOF crystals slowly growth on carbon cloth(CC),finally obtained the structure stability of the Co-MOF@CC electrode materials.The composite materials was further combined with a portable paper base to build the CoMOF@CC paper-based electrochemical sensor for catalytic oxidation of glucose.The experimental results show that the Co-MOF@CC paper-based sensor has a sensitive electrochemical response to glucose in alkaline medium.Successfully obtaining a wide linear range of 800 ?M ~ 5 mM and a low detection limit of 150 ?M.This system not only provides a new high-selective and high-precision method for glucose,but also a new idea for the efficient and portable detection of other substances in remote areas.