Application Research Of Colorimetric Analysis Based On Gold Nanomaterials In Analysis And Detection

Heavy metal ions have attracted more and more attention from all walks of life because they can seriously endanger human health by entering the human body through the food chain,interfering with the normal physiological functions of the human body.Among them,mercury ion(Hg²⁺)not only has great cytotoxicity,but also easily converts into more toxic methylmercury under the action of microorganisms,which has a great negative impact on human health and ecological environment.Therefore,it is significantly important to find a highly sensitive and selective method for the detection of Hg²⁺in the environment.At present,anions are playing more and more important roles in environmental,biological,pharmaceutical and industrial fields.Iodine ion?I^-?,as a necessary micronutrient for human normal growth,is of great important in the process of human growth and development,such as goiter and abnormal development of children caused by serious iodine deficiency and hyperthyroidism caused by excessive iodine intake.Therefore,it is of great significance to establish a simple and efficient method for the detection of I^-in the environment and human physiological environment.Recently,many articles have been reported for the detection of Hg²⁺.Among them,the colorimetric analysis based on gold nanoparticles?AuNPs?is the most common method.The reason is that it has the advantages of easy synthesis,high extinction coefficient,easy surface functionalization,good biocompatibility and high stability.However,most of the reported methods are based on the aggregation and surface functionalization of AuNPs.Therefore,it is particularly important to find a more novel method to detect Hg²⁺.Compared with Hg²⁺,there are few reported methods for the detection of I^-,and most of them involve complicated pretreatment process.Therefore,it is necessary to establish a simple and direct method for the detection of I^-.In this paper,a highly sensitive and selective detection method for Hg²⁺in environmental water samples based on the anti-aggregation mechanism of AuNPs is designed.On this basis,a sensor for direct detection of I^-in environmental and physiological systems is developed by using the strong complexation ability between Hg²⁺and I^-.The first chapter gave overviews of Hg²⁺and I^-,respectively,and mainly introduced the significance and the current research status of Hg²⁺and I^-.Meanwhile,various research methods were objectively evaluated and compared in this chapter.In the second chapter,the colorimetric sensor for Hg²⁺detection based on AuNPs was systematically studied,and the experimental conditions were successfully optimized.The selectivity and anti-interference ability of this method for Hg²⁺were further discussed.Finally,under the optimum experimental conditions,the detection of Hg²⁺in environmental water samples was successfully realized.The linear detection range of Hg²⁺was 0-680 nmol/L and the limit of detection?LOD?was 11.9nmol/L,which was lower than the limit concentration of Hg²⁺in drinking water?30nmol/L?established by the World Health Organization?WHO?.In the third chapter,a colorimetric sensor based on AuNPs-Hg²⁺system was discussed.Under the optimum conditions,the selectivity and anti-interference ability of this method were investigated,and it was successfully applied to the quantitative detection of I^-in environmental and physiological environments.The detection range was 0-800 nmol/L,and LOD was as low as 4.2 nmol/L.This value is lower than most reported methods for I^-detection and shows the superiority of the sensor we designed.