The research team of Wang Suhua of the Institute of Intelligent Machinery of the Chinese Academy of Sciences has made important progress recently in the field of rapid and sensitive detection of heavy metal ion contamination, established a new method of visual detection, and developed a new type of visual sensor. Relevant research results were published in the Analytical Chemistry of the American Chemical Society, the Journal of Materials Chemistry and the Nanotechnology International Journal of the Royal Society of Chemistry. The detection of trace heavy metal ions currently mainly depends on laboratory methods such as atomic absorption, atomic fluorescence, inductively coupled plasma, and mass spectrometry. Although the detection accuracy of these methods is relatively high, the instrument is expensive, expensive to run, requires many operations, and is time-consuming and labor-intensive to detect, and requires complex pre-treatment processes such as extraction, concentration, enrichment, or suppression of interference during measurement. In response to these problems, the researchers of the Institute of Intelligence designed and prepared specific organic chelating ligands for mercury ions, and reacted with mercury ions through ligand exchange reactions to form chelates, and further a rapid cation substitution reaction occurred on the surface of the luminescent quantum dots. As a result, the fluorescence efficiency of quantum dots changes, which enables highly sensitive and selective detection of mercury ions through changes in fluorescence intensity and color (Anal. Chem. 2012, DOI: 10.1021 / ac302822c). With the increase of mercury ion concentration, the peak position of the fluorescence emission gradually moves to the long wave direction, and the yellow light accompanying the quantum dots will gradually evolve into red light (as shown). The researchers further designed and assembled a paper sensor for mercury ions to achieve rapid visual detection of mercury ions in pure water and natural lake water. The visual detection method proposed by the research team has the advantages of not relying on large and expensive analytical instruments, naked eye observation, and fast response time. It can realize the rapid visual detection of trace heavy metal ions on site. The researchers also designed and developed a novel ratiometric fluorescent nanocomposite probe based on luminescent graphene oxide. Through the change of the ratio of the fluorescence of different colors of the probe, it can be used to visually detect and distinguish iron ions (Fe2 +) of different valence states. . Under ultraviolet light, as the concentration of Fe2 + increases, the fluorescence color of the probe changes from red to blue, thereby enabling visual detection of Fe2 + (Nanotechnology 2012, 23, 315502). In addition, the research team also developed electrode materials assembled from multilayer graphene oxide through multilayer self-assembly of graphene oxide. Combining the principle of electrochemistry, high selectivity and sensitive detection of copper ions can be achieved of Materials Chemistry 2012, 22, 22631). The research was supported by the National 973 Project "Basic Research on the Application of Nanotechnology to Remove Micro Pollutants in Drinking Water", the National Natural Science Foundation of China and the "Hundred People Program" of the Chinese Academy of Sciences. Pads for dogs,Dog cooling mat,Dog ice pack vest,Dog cooling sleep mat Ningbo Hejia Ice pack co. LTD, , https://www.cooling-pack.com