Study On The Detection Of Mercury Ions In Water Based On Gold Nanoparticles

Mercury,as a common heavy metal element in life,is extremely harmful to human health and the environment,and cannot be degraded by microorganisms.It is easy to be enriched in the living body,and poses a great threat to human health.When the concentration of mercury ions in the human body reaches 0.5-1.0 ?g/ml,the body will appear obvious symptoms of poisoning.Therefore,it is of great significance to establish a rapid and accurate method for determination of mercury ions in water.At present,there are already many methods for the detection of mercury ions in water,the main detection methods are mass spectrometry,electrochemical analysis,spectrophotometry,spectroscopy,etc.However,these methods are expensive,long analysis period,complicated sample pretreatment,So they can't meet the needs of practical analysis of mercury in daily life.Therefore,it is necessary to establish a simple,rapid,efficient and environmentally friendly mercury ion detection method.Gold nanoparticles(Au NPs)are widely used in material detection due to their unique characteristics surface plasmon resonance(SPR),so Au NPs material attracts great attention because of its superior properties that conventional large-sized materials do not possess.In recent years,the researchers take surface modification of gold nanoparticles,with the test substance to the occurrence of agglomeration or antiagglomeration role.The agglomeration and anti-agglomeration of gold nanoparticles are accompanied by the change of the colloidal gold nanoparticles,which provides the possibility for us to observe the change of the UV-Vis absorption spectra and detect the presence or absence of the analyses.In this paper,a rapid detection method based on gold colloid is proposed.Compared with the traditional mercury detection method,this method requires neither complicated sample treatment nor expensive experimental equipment,and the phenomenon could be observed by the naked eye,this method has very high sensitivity,and the detection limit as low as 54 nM,so it could be used for trace detection of mercury ions in water.First,Au NPs is synthesized by sodium citrate reduction method;then,the sample solution is added to the Au NPs and finally Dpy solution added into mixture solution.If there is no mercury ions in the sample solution,Dpy will combine with the gold nanoparticles,destroying its stable state,gold nanoparticles will agglomeration,the color of the solution changes from wine red to blue-black;if the sample contains mercury ions,Dpy will be preferred combined with the mercury ions,so gold nanoparticles continue to maintain a stable state,the color of the solution does not change.According to this obvious color change,or the analysis of the sample's UVvisible absorption spectrum,trace detection of mercury can be realized in water.