Enzyme-Free Glucose Electrochemical Sensor For MIL-53 Metal Organic Framework Compounds

Since the new century,diabetes has become a serious public health problem.It is important to control the change of blood glucose concentration at all times for the treatment of diabetes prevention.However,the commercially available blood glucose meters are enzyme-based glucose electrochemical sensors,and the enzyme is easily affected by environment,and affecting the test results.Moreover,these glucose sensors need to maintain enzyme activity during the manufacturing process,resulting in a complicated preparation process.Therefore,researchers have tried to make non-enzyme glucose electrochemical sensor electrodes using stable and inexpensive materials.For example:precious metals,transition metals,transition metal oxides,carbon materials and metal organic framework?MOF?.As a new material,MOF has the advantages of high porosity,large specific surface area,adjustable pore size and functionalization.Therefore,this paper synthesizes MIL-53 metal-organic framework for use in electrochemical non-enzyme glucose sensors.The main contents of the research are as follows:MIL-53?Fe?material was synthesized by hydrothermal method and an electrode was formed by adhering a conductive adhesive to the surface of the titanium metal substrate.The sensitivity of the electrode to glucose detection is 0.15302 mA·mM^–1·cm^–2;the linear range is 10?mol·L^–1 to 0.8 mmol·L^–1;the detection limit is 0.67?mol·L^–1?S/N=3?;the single-return electrode has five reproducible RSD=3.57%;the multi-electrode has five reproducibility of RSD=3.83%.A self-supporting MIL-53?Ni?electrode was synthesized by hydrothermal method and grown in situ on the surface of the foamed nickel for direct glucose detection.The sensitivity reached 26.03 mA·mM^-1·cm^–2;the linear range was 5?mol·L^–1 to 1.4 mmol·L^–1;the detection limit was 0.33?mol·L^–1?S/N=3?.The five-reproducibility RSD of the single electrode was 4.16%,and the reproducibility of the multi-electrode was five times RSD=3.77%.The self-supporting MIL-53?Ni?electrode and the MIL-53?Fe?electrode belong to the same MIL-53 type MOF,so they have excellent anti-interference,anti-toxicity,reproducibility and stability.Self-supporting MIL-53?Ni?electrodes have a self-supporting structure for higher sensitivity,lower detection limits and a wider linear range.And the self-supporting MIL-53?Ni?electrode has been applied to the actual serum sample,and the recovery rate is close to 100%.Because the bimetallic material has synergistic effect,the catalytic effect of glucose can be improved,so the self-supporting MIL-53?NiFe?bimetallic MOF is synthesized by hydrothermal method.The bimetallic MOF is directly grown on the surface of the foam nickel and directly applied to the detection of glucose.The detection limit was 0.13?M?S/N=3?;the sensitivity was 41.95 mA·mM^-1·cm^–2;the linear range was 2?M to 0.4 mM;The five-fold reproducible RSD of the single electrode was 3.67%;the five-fold reproducible RSD of the multi-electrode was 3.11%.And has excellent selectivity,anti-toxic ability and long-term stability.In order to remove the residual terephthalic acid molecules in the MOF channel and increase the linear range of the electrode,the electrode is heat treated to extend the linear range to 2?M to 1.6 mM while maintaining excellent electrode characteristics.Selectivity,long-term stability,anti-toxic properties.The application of the two bimetal electrode materials to the actual plasma test results is similar to the actual blood glucose concentration,which proves that the electrode has practical application value.