A preparation method of folic acid-modified carbon quantum dots and a method for detecting trace amounts of hexavalent chromium ions

Abstract

The invention discloses a preparation method of a folic acid-modified carbon quantum dot, and a method for detecting a trace hexavalent chromium ion by utilizing the folic acid-modified carbon quantumdot. According to the technical scheme, the folic acid-modified carbon quantum dot is used as a fluorescence probe and has better dynamic and thermodynamic properties and physical chemistry stability, favorable water solubility, high light resistance, surface property diversity, and easiness in chemical modification so as to form functional and environmentally friendly carbon nano-particles; thecarbon quantum dot prepared through the scheme does not contain heavy metals, so that the environment pollution can be reduced; the folic acid-modified carbon quantum dot has better sensitivity (1 to20ppb) on the trace hexavalent chromium. Finally, a fluorescent sensing method of the hexavalent chromium has the advantages of wide linear dynamic range, low spectral interference, high sensitivity and the like; a fluorescence photometer for detecting a fluorescence spectrum is lower in equipment cost, and no tedious processing is needed.

Description

technical field [0001] The invention relates to the technical field of detection of hexavalent chromium ions, in particular to a method for detecting trace amounts of hexavalent chromium ions by using folic acid-modified carbon quantum dots and a preparation method of the folic acid-modified carbon quantum dots. Background technique [0002] At present, in environmental monitoring and analysis, the determination methods of hexavalent chromium ions mainly include: diphenylcarbohydrazide spectrophotometry, enrichment-spectrophotometry, electrochemical analysis, ferrous ammonium sulfate titration, ion chromatography, Gas chromatography, catalytic kinetic methods, flame atomic absorption spectrometry and Rayleigh resonance scattering. Although these methods are sensitive and reliable, there are many problems, such as: 1) expensive large-scale equipment and instruments are required; 2) sample preparation and processing are complicated; 3) selectivity and anti-interference ability...

AI Technical Summary

Problems solved by technology

Although these methods are sensitive and reliable, there are many problems, such as: 1) expensive large-scale equipment and instruments are required; 2) sample preparation and processing are complicated; 3) selectivity and anti-interference ability are crossed; 4) on-site rapid 5) High technical requirements for operators

[0003] In addition, 1) atomic absorption spectrometry, atomic emission spectrometry and mass spectrometry are the most commonly used detection methods for hexavalent chromium. These methods are suitable for actual sample analysis, but they are expensive and difficult to achieve on-line monitoring; at the same time, trace detection requires Enrichment of samples is cumbersome and time-consuming; 2) The electrochemical method can realize the online monitoring of arsenic, but this method requires toxic substances such as potassium ferricyanide, the data is unstable, and it is less affected by the turbidity and chromaticity of the water body. 3) The online monitoring of hexavalent chromium by spectrophotometry is the most widely used, but the detection limit is as high as 40ppb, which is greatly interfered by the pH of water samples, other ions and color (turbidity)