Method for selective sensitive mercury ion detection based on gold nano-cluster fluorescence ratio detection test strip

Abstract

The invention relates to the technical field of nano materials, and in particular to a method for selective sensitive mercury ion detection based on a gold nano-cluster fluorescence ratio detection test strip. The method comprises the following steps: firstly, preparing gold nano clusters with two different fluorescence emissions, that is, a bovine serum albumin coated gold nano-cluster (BSA-Au NCs) and cysteine coated gold nano-cluster (Cys-Au NCs); according to an appropriate proportion, concentration and pH conditions, preparing a fluorescence ratio probe, wherein the detection range is 50 nM-3 [mu]M, the minimum price detection limit is 9 nM, and the fluorescence ratio probe is as shown in figure 1 in the specification; finally preparing the fluorescence ratio detection test strip. By adopting the method, the fluorescence ratio detection test strip is prepared under gentle conditions and is applied to detection on mercury ions in an actual water sample.

Description

technical field [0001] The invention belongs to the technical field of nanometer materials. Background technique [0002] Due to their large surface area and diameter close to the electron Fermi wavelength, fluorescent metal nanoclusters have different properties from larger particles or bulk metals, such as catalytic performance, magnetic properties, and fluorescent properties, so they can be used in catalysis, drug delivery , medical treatment, environmental monitoring, and biological imaging are widely used. With the development of industry and agriculture, the gradual promotion of environmental governance, and the diversification of food production, in many industrial production processes, waste liquid and waste discharge monitoring, food safety testing and The detection of domestic water involves the detection of heavy metals. Nowadays, the detection methods for heavy metals mainly include: cryo-atomic absorption spectrometry, X-ray absorption spectrometry, inductively ...

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Problems solved by technology

[0002] Due to their large surface area and diameter close to the electron Fermi wavelength, fluorescent metal nanoclusters have different properties from larger particles or bulk metals, such as catalytic performance, magnetic properties, and fluorescent properties, so they can be used in catalysis, drug delivery , medical treatment, environmental monitoring, and biological imaging are widely used. With the development of industry and agriculture, the gradual promotion of environmental governance, and the diversification of food production, in many industrial production processes, waste liquid and waste discharge monitoring, food safety testing and The detection of domestic water involves the detection of heavy metals. Nowadays, the detection methods for heavy metals mainly include: cryo-atomic absorption spectrometry, X-ray absorption spectrometry, inductively coupled plasma mass spectrometry, and cryo-fluorescence spectrometry. However, these methods Ordinary laboratories cannot be used, and they also lack sensitivity and immediacy of detection. Therefore, it is urgent to establish a convenient, fast and sensitive method, and design and synthesize a stable, fluorescent fluorescent probe with strong fluorescence properties is very promising.

[0003] In recent years, there have been many studies on the synthesis of new metal nanoclusters as chemical sensors for detecting metal ions, but they mainly focus on the specific response of monochromatic fluorescent metal nanoclusters to heavy metal ions. However, monochromatic fluorescent nanoclusters only The presence or absence of heavy metal ions in the system can be qualitatively judged by whether the fluorescence is quenched or not, and the content of metal ions in it cannot be known, and a fluorescence spectrometer must be used. Therefore, two metal nanoclusters with different fluorescence emissions can be designed, according to Proper ratio mixing to make a fluorescence ratio probe. Different concentrations of metal ions quench one of the metal nanoclusters to different degrees, so that the fluorescence color of the test paper has a gradual change process, which can realize the visualization and quantification of heavy metal ion detection. It does not need to be measured by expensive instruments. The ratio test paper of dual fluorescence emission that has been reported today usually contains semiconductor quantum dots, carbon quantum dots and organic fluorescent dyes. However, the fluorescence stability of fluorescent dyes is poor and cannot be stored for a long time ; while the synthesis of semiconductor quantum dots usually takes a long time and the photobleaching phenomenon is more serious, the conditions required for the synthesis of carbon quantum dots usually require high temperature and high energy consumption. The synthesis method of metal nanoclusters is simple, the conditions are mild, and the time-consuming is relatively It is short and has high fluorescence stability, so it is an ideal material for fluorescence ratio probes.

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