Design And Realization Of Mercury Ion Detection System Based On Small Size Gold Nanords

Mercury is one of the most common toxic metals,as mercury ion?II?is persistent,highly bio-concentrated and easy to migrate,it is considered to be one of the most toxic and polluted heavy metal ions in the environment.Currently,the mercury ion?II?detection systems and methods can achieve high selectivity and low detection limits,but are limited in detection sensitivity and detection time in practical applications.Therefore,exploiting a mercury ion?II?detection system with low cost,rapidity and high sensitivity has important research significance and realistic demand.According to the above problems,small-sized gold nanorods were prepared in this paper,and a trace amounts of mercury ions?II?detection system used optical probe was built which based on the localized surface plasmon resonance characteristics.At the same time,longitudinal SPR peak??_L?,length-to-diameter ratio R and the dielectric constant?of the gold nanorods were tracked during the detection process.What's more,the mechanism of the detection system designed in this paper was studied from this perspective.The specific research contents are as follows:?1?A rod-like nanogold was prepared in one step using a seedless growth method.The effects of experimental parameters on the morphology,dispersity and stability of gold nanorods were studied in detail.The optimal conditions for the preparation of gold nanorods were obtained:the concentrations of CTAB,AgNO₃,AA and NaBH₄ were 0.08 mol/L,100?mol/L,0.1 mmol/L and 1.5?mol/L,respectively.The stirring time was 20 s and reaction time was 5 h,supplemently.?2?Based on the unique Longitudinal-Local Surface Plasmon Resonance?L-LSPR?of rod-nanogold probes and the strong physicochemical interaction between gold?0?and mercury?0?,highly sensitive mercury ion?II?detection system was established using unmodified Gold nano-rods.In this paper,the factors that affect the detection effect of mercury ions?II?were studied in detail:pH value,reducing agent concentration,stabilization time and reaction time.On this basis,the detection limit,linear range,selectivity and detection recovery with the actual spiked water sample of the Hg?II?detection system were tested respectively.?3?Through the measurement of Au NRs for the measurement of mercury ion processes,the intermediate electrical constants,aspect ratios,and longitudinal SPR peaks were traced.Then the relationship among the three factors was discussed,and the role of the three factors in mercury ion detection was studied.According to the experimental results,the simulation results for the relationship between?,R,and?_L in the existing studies were corrected.The dielectric of gold nanorods was regulated by S^2-,the relationship between?,R,and?_L of the S^2--Au NRs for Hg²⁺detection system was further studied.Using S^2--Au NRs as a probe to test mercury ions in water,the detection performance of the mercury ion measurement system was analyzed and evaluated from the linear range,detection limit,sensitivity and selectivity.