Preparation Of Pt(Pd) Alloy Nanostructures And Their Applications In Detection

Hydrogen peroxide plays an important role in human metabolism,not only participates in the regulation of biological activities,but also can be regarded as an indicator of disease diagnosis.Nitrite is often added to food to change its color and flavor.At the same time,excessive hydrogen peroxide or nitrite will cause different degree of damage to human organs,so trace detection of hydrogen peroxide and nitrite are very important.The increasing demand for sensing a broad range of molecules at low concentration with high specificity has motivated the development of analysis and detection technology.Noble metal nanomaterials exhibit excellent physical and chemical properties,they play an important role in developing new detection technologies and improving existing technologies to improve sensitivity and selectivity.In this paper,based on the catalytic performance of platinum and palladium nanomaterials,H₂O₂ and nitrite have been detected with high sensitivity and selectivity,including:1.Etched PtCu nanowires as a novel peroxidase-like mimic were synthesized through hydrothermal reaction and chemical etching process.H₂O₂ decomposed into hydroxyl radicals which oxidized TMB in the presence of E-PtCu NWs and the the color of product was blue.Based on the high peroxidase-like activity,a colorimetric sensor for H₂O₂ was established.It possessed a good linear relationship between H₂O₂ concentration and the absorption intensity in a range of 0.1-300?M,and the detection limit?LOD?was 0.06?M?S/N=3?.The colorimetric sensor was applied to detect H₂O₂ in milk and contact lens solution successfully.Furthermore,a high sensitive test strip was also designed which can provied a low cost and quick method to detect H₂O₂.2.PdFe ultrathin nanosheets were prepared by hydrothermal method and the electrochemical nitrite sensor was designed.PdFe nanosheets showed specific catalytic activity for oxidation of nitrite.The nitrite sensor possessed high sensitivity and selectivity.A linear relationship between nitrite concentration and electrical signal was in the range of1 to 160?M.The LOD value was found to be 0.12?M?S/N=3?.The sensor has been applied to the determination of nitrite in tap water and sausage successfully.3.Au@PdNi core-shell nanoparticles were prepared and used for electrochemical detection for nitrite.Based on the highly catalytic activity towards the oxidation of nitrite,a sensitive electrochemical method for nitrite detection was designed.The linear response range for nitrite is 1 to 453?M.The LOD value was calculated to be 0.1?M?S/N=3?.The nitrite sensor was applied to detect nitrite in river water successfully.