Research Of Surface Enhanced Raman Spectroscopy In The Detection Of Mercury Ion

As a kind of heavy metal, mercury ion (Hg2+) is very toxic to humans, animals and plants, it is very toxic and can produce irreversible damage effects on the nervous system, kidneys, liver and other tissues, the impact on food and environmental safety is a threat to human health. Therefore, establishing a rapid, sensitive and convenient mercury ion detection method plays an important role in protecting human health. This article introduces the detection methods are as follows:1. Surface enhanced Raman spectra Based on the lateral tomography technology for Hg2* detectionThis method is based on the classic T-Hg2+-T recognition system, first, T-rich Hg21+ nucleic acid aptamer was assemble on the surface of Raman reporter modified AuNPs, on one hand, it was bound with the same T-rich test line (T line) probe through T-Hg2+-T mismatch and show the color of AuNPs, one the other hand, the aptamer also can be captured by the control line (C line) probe through the complementary base pairing showing the color as well. The preliminary qualitative analysis of Hg2+ concentration in the system was by visual observation, then, applying surface enhanced Raman spectrum (SERS), the signal intensity can still be detected in the blind zone, thus, the detection sensitivity was improved on the basis of chromatographic techniques. Furthermore, selecting Au@Ag as the substrate instead of AuNPs, the signal application result was more satisfactory, and the final sensitivity can be achieved O.lppb.2. Traditional surface enhanced Raman spectra for Hg2+ detectionThis method is also established on the basis of Hg2+ aptamer, T-rich Hg2+ nucleic acid aptamer was assemble on the surface of Raman reporter modified AuNPs, the distance between the gold nanoparticles was reduced by T-Hg2+-T recognition system as Hg2+ exist, subsequently, a hot spot formed between two nanoparticles and electromagnetism intensity strengthened in the region, so the Raman signal of the Raman reporter located in the hot spot enhanced accordingly. With this method, detection sensitivity is much higher than that with colorimetry. The final detection sensitivity reached 0.01 nM with SERS, and when the mercury ion concentration in the range of 10-11-10-8M, the Raman signal intensity and the logarithm of the concentration of mercury ions showed a good linear relationship.3. Enhanced SERS detection of Hg2+On the basis of conventional Raman detection method, by a pair of oligonucleotide probes complementary to each other, small particle size of silver nanoparticles (AgNPs) were bind on the surface of AuNP, increasing and enhancing the the electromagnetic intensity in hot spots field between two gold nanoparticles, as a result, the reporter signal was further enhanced leading to sensitization effect. We optimized the proportion of two types of nanoparticles and complementary probe concentration, then obtained a final sensitivity of mercury ion with 0.01 pM, and in the range of 10-11-10-8 M, Raman signal intensity and the logarithm of mercury ion concentration is also had good linear.