Quantitative detection device and method for arsenic ions in water based on laser photo-thermal interference

Abstract

The invention belongs to the field of optical biochemical detection. Traditional detection methods comprise an atomic absorption spectrometry method, an atomic fluorescence spectrometry method and other large instrument methods which are characterized by high accuracy and quantitative detection but have defects of complex operation, long detection period, high equipment cost and the like. the invention provides a quantitative detection device and method for arsenic ions in water based on laser photo-thermal interference. Two lasers pass through a dichroscope and are reflected by a plane mirrorto irradiate a detection area; arsenic ions in the solution are specifically combined with an aptamer chain wrapping the surface of nanogold; a high-concentration NaCl solution is added to cause aggregation of the gold nanoparticles; the solution is changed from wine red to bluish violet; laser beams irradiating a micro-channel interfere with each other and are received by a photoelectric detector, via an photothermal effect, the temperature of the solution is changed after the solution absorbs light to cause movement of interference fringes, the concentration of arsenic ions in water is quantitatively detected by measuring the photothermal signal difference of the two laser beams, and the device and method can be widely applied to the fields of environment, food detection, medical diagnosis and the like.

Description

technical field [0001] The invention relates to the technical field of optical biochemical detection, more specifically, it relates to a device and method for quantitative detection of arsenic ions in water based on laser photothermal interference. Background technique [0002] In recent years, with the continuous improvement of the degree of industrialization, the discharge of industrial waste water has also increased. In order to reduce costs, some enterprises directly discharge the produced industrial waste water into rivers without treatment, resulting in varying degrees of pollution to drinking water sources. Pollutants seriously damage people's health. Trivalent arsenic ion As(Ⅲ) is one of the pollutants in water, which can damage the small arteries and capillaries of the human body, and cause serious damage to internal organs, causing cancer or even death. Therefore, the detection of As(Ⅲ) in water is particularly important. Traditional As(Ⅲ) detection methods mainl...

AI Technical Summary

Problems solved by technology

In 2013, Chen Ailiang and others used the specific combination of aptamer chain and sulfonamide antibiotic (SDM). When SDM exists in the substance to be detected, the combination of SDM and aptamer chain causes the aptamer chain to detach from the surface of gold nanoparticles. Under the action of gold nanoparticles aggregated, the color of the solution changed from red to blue-purple, the relationship between the maximum absorption peak of the solution and the concentration of SDM was established, and the quantitative detection of SDM was realized (Chen, A. L.; Yang, S. M. et al. High sensitive rapid visual detection of sulfadimethoxine by label-freeaptasensor, Biosens. Bioelectron., 2013, 42, 419–425.) However, the above-mentioned method still needs to rely on large-scale instruments such as spectrophotometers and fluorescence spectrometers. There are large consumption of samples and reagents, and long detection time. Difficult to integrate, difficult to lower the detection limit and other issues

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