Construction Of MOF Derived Transition Metal-carbon Matrix Composites And The Electrochemistry Studies On The Determination Of Small Biomolecules

It will lead to some diseases when the concentration of small molecules in the body at an abnormal level.Hence,it has a significant meaning that analyzing small biological molecules in a concentration level to guarantee health conditions.Compared with other determination methods,electrochemical methods are widely used in many aspects owing to its low cost,excellent sensitivity,supernal selectivity and ease of miniaturization for small volume samples.This paper masterly designed and successfully constructed three kinds of nanoporous carbon-based composite materials derived from metal organic framework（MOF）:Ni@CHS/rGO,Mo_xC@C and WO₂/W@C as the modified electrode materials.And it realized the analysis and determination toward small biological molecules about ascorbic acid（AA）,dopamine（DA）,uric acid（UA）,thymine（T）,adenine（A）,guanine（G）,and cytosine（C）.The follows are main contents of this paper:Designed and synthesized bayberry-like porous Ni@carbon hollow nanosphere/rGO hybrid-Ni@CHS/rGO（by hydrothermal and calcining process）as the electrode material applied in electrochemical for simultaneous detection small biomolecules of AA,DA and UA.3D porous Ni@CHS/rGO composite not only possess carbon matrix to increase the electron transfer rate and sustaining highly electrical conductivity of Ni metal,but also permitted releasing and uptaking of electrolytes and increased adsorption capacity of analytes due to introduction of rGO and a hollow construction.Consequently,such a fascinating structure exhibited excellent electrocatalytic activity and towards AA,UA and DA.Through the studying of the pH and scan rate,the electron transfer process and reaction mechanism were discussed.For simultaneous analyse of three targets,the fabricated sensor exhibited wide linear range and low detection limit,the sensor also exhibited high sensitivity,outstanding stability,excellent anti-interference ability.Moreover,the captivating sensor was resoundingly applied for the quantitative analysis of AA,DA and UA in vitamin C tablets and human urine samples with satisfactory recovery,which manifests its viability application for practical analysis.Multiporous Mo_xC@C nanosphere was synthesized and applied as a new charming electrode material for highly sensitive simultaneous detection of guanine and adenine.By introduction of Mo metal species into the Cu-MOF as co-precursor,molybdenum carbide nanosphere（Mo_xC@C）was prepared via a simple calcining routine and a further etching the metallic Cu process.The porous structure of Mo_xC@C complex increased contact area with the analytes and exposed more active sites.The obtained Mo_x C@C showed a high electrical conductivity where well-dispersed MoxC nanoparticles（NPs）were encapsulated in porous carbon matrix.As-fabricated novel 3D porous architecture Mo_xC@C nanosphere exhibited a potent and persistent electro-oxidation behavior followed by well-separated oxidation peaks（peak to peak voltage is about 350 mV）toward A and G by differential pulse voltammetry（DPV）.Electron transfer process and reaction mechanism have been studied by pH and scan rate.3D Mo_xC@C also revealed high selectivity and sensitivity,obtained wide linear range and low detection limit.The proposed procedure was successfully applied to detect G and A in human urine and serum samples with satisfactory recovery,which manifests Mo_xC@C/GCE possesses excellent stability and anti-interference ability and its viability application for practical analysis.3D hierarchical porous WO₂/W@C carbonsphere nanocapsules（WO₂/W@CSPs）composite material was synthesized and served as electrode material of the sensor applied for highly sensitive simultaneous detection of T and C.The porous structure of WO₂/W@CSPs reduced the electron transfer path and increased the electron transfer efficiency.And WO₂/W nanoparticles have abundant active sites and excellent electrical conductivity.The electrochemical behavior and reaction mechanism of T and C were studied experimentally.WO₂/W@CSPs/GCE sensors are applied for trace analysis of T and C and showed wide linear range and high sensitivity.After investigating of possible interfering substances in the real sample,it is proved that WO₂/W@CSPs/GCE sensor can be successfully applied in the actual analysis of blood and urine samples.