Three-electrode integrated electrochemical sensor based on microelectrode array

Abstract

The invention discloses a three-electrode integrated electrochemical sensor based on a microelectrode array. The sensor comprises the bismuth film modified microelectrode array (gold working electrode), a silver/silver chloride electrode (reference electrode) and a platinum electrode (counter electrode). The three electrodes are prepared through a standard MEMS technology, and multiple discs at equal intervals are evenly distributed on the gold electrode to serve as the microelectrode array. In the electrochemical detection process, heavy metal gathering and dissolving-out reacting occur on the microelectrode array, and the surface of the microelectrode array is modified with a bismuth film in order to increase the detection type of heavy metal and expand the detection range of the heavy metal. The surface of the silver electrode is electroplated with silver chloride to form the Ag/AgCl reference electrode. The platinum electrode serves as the counter electrode and forms an access with the working electrode. Difference pulse stripping voltammetry is utilized for determining the concentration of the heavy metal, and a result shows that the sensor is high in detection sensitivity, low in detection limit and high in signal-to-noise ratio; the sensor is easy and convenient to operate, needs a small quantity of samples, can be used for rapidly detection heavy metal on site and is capable of efficiently monitoring environmental pollution in real time.

Description

technical field [0001] The invention relates to the technical field of electrochemical sensors and heavy metal detection, in particular to a three-electrode integrated electrochemical sensor based on a microelectrode array. Background technique [0002] The safety of food, drinking water and oceans is a widespread and growing concern. Among them, due to the cumulative effect of heavy metals in the food chain, heavy metal pollution is particularly harmful to human health and the balance of the ecological environment. Therefore, real-time rapid on-site detection of heavy metals is very important. [0003] At present, heavy metal detection methods include atomic spectroscopy, inductively coupled plasma mass spectrometry, electrochemical analysis and other methods. Atomic spectroscopy and inductively coupled plasma mass spectrometry have high sensitivity, low detection limit, and good repeatability, but they have high requirements for the experimental environment, expensive in...

AI Technical Summary

Problems solved by technology

The traditional three-electrode detection requires a large test sample, and a series of operations such as installation and fixing are cumbersome, and the change of the relative position of the working electrode and the counter electrode will introduce interference, which reduces the repeatability and accuracy of the test.

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