Method of manufacturing an ultra-microelectrode

Abstract

The present invention discloses a method of manufacturing an ultra-microelectrode and is characterized by sealing the top end of a capillary tube by adopting a flame fusing method, plating a dielectric film by adopting a cyclic voltammetry method for the first time and obtaining the top end of an ultra-microelectrode by using an electric shock method. Comparing with the traditional technology, the present invention discloses an ultra-microelectrode having a top end with a minimum diameter of 300-1000nm, having a uniform compact uneasy-falling dielectric film, and the size is controllable, thesensitivity is high, the steady-state current is reduced from 10[-7]A to 10[-9]A, the ultra-microelectrode can be tested in an organic system, and thus, application fields of the ultra-microelectrodeis widened greatly. The method has characteristics of simple manufacturing and low cost, and the manufactured ultra-microelectrode has a perfect electrochemical performance and can be used for singlecell detecting and probes of scanning electrochemical microscopes.

Description

technical field [0001] The invention relates to a manufacturing method of an ultramicro electrode, which is especially suitable for a scanning electrochemical microscope (SECM) probe. Background technique [0002] Due to its own characteristics, ultra-microelectrodes have been widely used in analytical chemistry, especially in the field of life sciences, such as biological cell analysis, single-molecule analysis, solid-state electrochemistry, chemical kinetic parameter determination, and trace substance determination. Secondly, ultramicroelectrodes are also widely used as probes in scanning electrochemical microscopes to characterize the morphology of substrates. The production of traditional probes is complex, costly, and time-consuming. Generally, it takes two weeks to make a probe. [0003] Ultra-micro electrodes are generally sealed with epoxy resin at one end, and then the unsealed surface of the other end is immersed in insulating varnish or epoxy resin, and the tip i...

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Problems solved by technology

[0004] 1. Sealed with epoxy resin, epoxy resin will inevitably leak in the solution during use, resulting in the appearance of noise signals during the detection process, which greatly reduces the sensitivity of the detection, resulting in the detection of certain traces The system cannot detect

[0005] 2. Using epoxy resin to seal, not only greatly reduces the sensitivity, but also pollutes the measured object, thus making the measurement result inaccurate

[0006] 3. Due to the limitation of epoxy resin, this kind of electrode is not suitable for detection and modification in organic solvents, which makes the experiment impossible, which limits the scope of use of this electrode

[0007] 4. The electrode surface is coated or applied with a constant voltage (generally 2V-5V) to polymerize an insulating layer. It is required that the electrode wire should not be too thin. Otherwise, due to surface tension, the exposed length will be too long, which will cause multiple cracks on the electrode wire paint surface. It cannot be covered on the electrode wire, or the paint or insulating layer covered on the surface of the electrode wire is uneven and not dense, and the diameter of the electrode does not meet the requirements of μm, so it cannot be used for the detection of single cells in biological systems

[0008] 5. The tip of the traditional ultra-micro electrode is obtained by manually cutting the tip of the electrode coated with an insulating layer with a blade, which will inevitably cause damage to the insulating layer above the cutting surface during operation, so that the electrode The surface is not smooth, and the flatness of the molecular level cannot be reached, and there are errors in the measurement results, and even the failure of the electrode production

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