Electrochemical sensor based on metal organic framework-vertical graphene composite structure and preparation method thereof

Abstract

The invention belongs to the technical field of biosensors, and in particular discloses an electrochemical sensor based on a metal organic framework-vertical graphene composite structure and a preparation method thereof. The preparation method specifically comprises the following steps: (1) growing vertical graphene on a stainless steel substrate; (2) synthesizing various different metal organic framework (MOF for short) materials such as ZIF-8, KAUST-1 and Ni-MIL-77 by taking the vertical graphene on the stainless steel substrate as a template; and (4) constructing the electrochemical sensorby taking the MOF-vertical graphene composite nanostructure as an electrode material. The electrochemical sensor has higher electric conductivity, larger specific surface area and more types of responsive substance surfaces, and the preparation method is relatively clear, different MOFs can be made by selecting materials according to performance of chemical reactions directly, and the spatial structure of the MOF material can be altered according to performance demand, so that the electrochemical sensor which further meets the demand can be manufactured more easily, and is wide in applicationrange.

Description

technical field [0001] The invention belongs to the technical field of biosensors, in particular to an electrochemical sensor based on a metal organic framework-vertical graphene composite structure and a preparation method thereof. Background technique [0002] A biosensor is a device used to monitor a living system or a biochemical substance associated with it. Because of its advantages such as good selectivity, high sensitivity, fast analysis speed, simple and low-cost instruments, it is an important part of current scientific research. It has been highly valued and widely used in clinical diagnosis, environmental monitoring, drug screening, food safety and agricultural testing. Among them, electrochemical sensors are frequently used in limited space applications due to their advantages of simple operation, low cost, fast response, and high sensitivity. By improving the performance of some sensitive functional materials, it is of great significance for the development of ...

AI Technical Summary

Problems solved by technology

[0006] First, among the carbon nanomaterials, carbon nanotubes, graphene, acetylene black, and carbon nanofibers all have the general characteristics of electrochemical sensors, but the functions of these carbon nanomaterials are relatively single. The performance improvement of the sensor has relatively large limitations, and the response rate still cannot meet the requirements of medical applications;

[0007] Second, metal and metal oxide nanoparticles, similar to carbon nanomaterials, are composed of a single conductive material, which is not conducive to the development of electrochemical sensors in a more diverse direction, and cannot be both conductive and sensitive. Extraordinary ability;

[0008] Third, transition metal complexes play an important role in the field of electrochemical sensing, but transition metals need to be combined with other substances to form complexes. Only the limitations of transition metals themselves are relatively large, and they are still relatively conductive compared to graphene. As far as excellent materials are concerned, the conductivity of transition metal complexes is still relatively weak;

[0009] Fourth, the conductive polymer modified electrode has the advantages of high active group concentration, accelerated electron transfer, large chemical influence signal, and good stability, but the specific surface area is relatively small

Carbon nanomaterials, metal and metal oxide nanoparticles, transition metal complexes, and conducting polymers may take longer to develop and may be more difficult to improve in terms of performance, especially due to the inherent nature of the materials. Limitations lead to difficulties in improving the performance of electrochemical sensors

Due to the high requirements of measurement accuracy and response time in medicine or engineering, it is more difficult to find improvements in the original electrochemical materials, and the requirements for different applications and different substance detection are also different. For the application of chemical sensors in all aspects of life, especially in medicine, it is not enough to use existing electrochemically sensitive materials

At the same time, although MOFs materials are widely used in electrode materials and have shown excellent potential in electrochemical sensing, there are still many shortcomings and improvements in MOFs materials.

Most MOFs have poor stability due to the reversible nature of the coordination bond. Many synthesized MOFs are micron-scale materials, resulting in weak bonding between MOFs and sensor surfaces, and most MOFs have poor conductivity.

Inherent defects of MOFs limit their wide application in sensors

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