Study On Enzyme Free Glucose Sensing Based On NiCu Bimetallic MOF

The quantitative detection of glucose concentration is of great significance for the clinical diagnosis and treatment and daily care of patients with diabetes mellitus.At present,commercial glucose sensors are mainly based on electrochemical glucose oxidase（GOx）method to realize the quantitative detection of glucose in blood.However,glucose oxidase method is easily affected by the detection environment.Therefore,researchers are committed to the development of enzyme-free glucose sensor.Recent studies have shown that metal organic frameworks（MOF）,as a carrier material with high porosity and large specific surface area,have potential applications in enzyme-free glucose sensors.However,there are still some problems in carbonization of MOF materials,metal particles are easily aggregation and falling off during electrochemical test and the yield is low.In this paper,Ni MOF and Cu doped Ni Cu bimetallic MOF nanomaterials were designed and synthesised,and applied to the enzyme-free electrochemical detection of glucose.The main contents of the study are as follows:（1）Ni-MOF nanoflowers were prepared by hydrothermal method,the three-dimensional structure was formed by cross-linking of nanosheets.This cross-linking structure can expose more active sites,and enhance the electrocatalysis of glucose,and applied to glucose enzyme free detection.The results showed that the sensitivity of Ni MOF electrode to glucose is as high as5759μA·m M^-1·cm^-2,the detection range is 0.005-1.63 mmol·L^-1,and the minimum detection limit is 2.5μmol·L^-1（S/N=3）.Moreover,the Ni MOF electrode have good long-term storage stability,anti-interference and anti chloride toxicity performance.I-t also showed good accuracy in the actual detection of human serum samples.（2）Cu doping was introduced into the Ni-MOF materials to improve the stability of Ni active center by the synergistic effect between bimetallic elements,thus enhancing the catalytic performance of Ni-MOF materials for glucose.A series of Ni Cu bimetallic MOF nanosheets were prepared by adjusting the Ni/Cu ratio,which were used for enzyme-free detection of glucose.Among them,Ni Cu-MOF-6nanosheet material with the best catalytic performance has higher electrochemical active area than Ni-MOF material.The test results show that the sensitivity of Ni Cu-MOF-6 modified electrode is 1832μA·m M^-1·cm^-2,and the detection range is0.02-4.93 mmol·L^-1,which is three times of that of Ni-MOF material,and the minimum detection limit is 20μmol·L^-1（S/N=3）,which has good anti-interference performance.In addition,compared with Ni-MOF,Cu doping significantly improved the long-term storage stability and anti Cl^-toxicity performance of the material.The detection results of human serum of actual samples were also close to those of blood glucose meters used in the market,indicating that the electrode has certain practical application value.