Electrochemical ultra-micro compound electrode and preparation method thereof

Abstract

The invention discloses an electrochemical ultra-micro compound electrode and a preparation method thereof. The method adopts optical lithography; after a pattern of an ultra-micro electrode is transferred onto a substrate, photoresist is thrown and coated again, and is directly taken as an insulation encapsulating layer; and the photoresist on the tip part of the electrode is etched through exposure to form a micro electrolyzer. The method has simple manufacturing steps, can massively prepare electrode at one time, and ensures accurately controllable electrode exposing areas. The micro electrolyzer prepared has good electrochemical characteristics, such as high mass transfer rate, high signal to noise ratio, high current density and the like in experimental tests. The electrode has fixed position, so a result with good repeatability can be obtained. The electrolyzer has a capacity of less than 1pL, and can be used for accurately confining and detecting trace electrolyte. The results show that the devices have good trace detection capacity.

Description

technical field [0001] The invention relates to an electrochemical ultrafine composite electrode and a preparation method thereof. Background technique [0002] Ultramicroelectrode is a type of electrode whose size is smaller than the thickness of the diffusion layer in the experiment, that is, an electrode with a certain dimension (such as radius) not greater than 25 μm. Due to the excellent electrochemical characteristics of ultra-microelectrodes such as high mass transfer rate, small time constant, low IR drop, high signal-to-noise ratio, and high current density, they are widely used in nanobiosensors, single-cell analysis, trace and trace detection, electrochemical Kinetic research, electrocatalytic reaction and many other fields have shown special advantages and great application potential. However, under certain experimental conditions, such as the detection of single-cell extracellular neurotransmitters and information molecules, the detection of single or several e...

AI Technical Summary

Problems solved by technology

However, under certain experimental conditions, such as the detection of single-cell extracellular neurotransmitters and information molecules, the detection of single or several electrochemically active molecules, etc., only ultra-microelectrodes as working electrodes cannot meet the requirements of the experiment. The reference electrode and the counter electrode also need to be reduced to the micro-nano scale to realize the miniaturization of the entire electrochemical test system

Previous research work often uses the method of moving two to three microprobes into the test environment to achieve the experimental purpose, but the preparation of microprobes and their manipulation are delicate and complicated, and it is not easy to control

There are also some works that try to integrate two electrodes or three electrodes in a miniature electrochemical sensor, such as the preparation process of two composite microelectrodes disclosed by the Chinese Patent Office (application numbers are 03137469.7 and 200610062913.1), and have obtained relatively high Sensitivity and accuracy, the disadvantage is that this process involves too much manual operation, especially the parts of insulation encapsulation and electrode cutting, which are delicate and difficult to control, and cannot meet the requirements of a large number of controllable preparations

At the same time, the configuration scale of the glass capillary as the insulating support is at least tens of microns, which limits the further miniaturization of the combined electrode.

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