A kind of enzyme-free superoxide anion electrochemical sensor and its preparation method and application

Abstract

The invention provides a production method of an enzyme-free superoxide anion electrochemical sensor. The production method comprises the following steps: functionalizing multi-walled carbon nano-tubes with L-cysteine to obtain Cys-MWCNTs, and depositing silver nano-particles on the surface of a Cys-MWCNTs modified electrode through an electrochemical technology to obtain the enzyme-free superoxide anion electrochemical sensor. The invention also provides the enzyme-free superoxide anion electrochemical sensor produced through the method, and an application of the enzyme-free superoxide anion electrochemical sensor. The catalysis effect of the silver nano-particles on active oxygen is used to substitute SOD enzyme for the first time in order to detect superoxide anions. The method has the advantages of simplicity, easiness in operation, difficult inactivation and realization of long-term preservation and use. The modified electrode is successfully applied to detection of the superoxide anions released by living cells (PC12). The modified electrode constructed in the invention has the characteristics of very good electrochemical response to O<2>.<->, wide linear range, high sensitivity, short response time, good stability and good repeatability.

Description

technical field [0001] The invention relates to an enzyme-free superoxide anion electrochemical sensor and its preparation method and application. Background technique [0002] Reactive oxygen species (ROS) are important intracellular signaling molecules that mainly regulate DNA damage, protein synthesis, apoptosis and so on. Among them, the superoxide anion (O 2 · − ), as one of the most important and active ROS, is involved in many physiological and pathological processes and can cause damage to biological organs. In recent years, O 2 · − The relationship between concentration and human health has attracted great attention. From the perspective of in vivo application, O 2 · − The dynamic detection linear range is wide, not only in the molar concentration of millimolar and micromolar, but even needs to be extended to the molar concentration of nanomolar level. At the same time, since O 2 · − It is extremely unstable and easily decays into other active oxygen units....

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Problems solved by technology

However, electron transfer is difficult because the active center of the enzyme is covered by surface proteins

In addition, enzymes are expensive, easy to inactivate, have high environmental requirements, and the preparation of enzyme electrodes is cumbersome and difficult to store. These shortcomings greatly limit the development of enzyme sensors.

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