Gold nanoparticles hosted in a water-soluble silsesquioxane polymer applied as a catalytic material onto an electrochemical sensor for detection of nitrophenol isomers

摘要

The water-soluble 3-n-propyl-4-picolinium silsesquioxane chloride (Si4Pic~+Cl~-) polymer was prepared, characterized and used as a stabilizing agent for the synthesis of gold nanoparticles (nAu). The ability of Si4Pic~+Cl~- to adsorb anionic metal complexes such as AuCl_4~- ions allowed well-dispersed nAu to be obtained with an average particle size of 4.5 nm. The liquid suspension of nAu-Si4Pic~+Cl- was deposited by the drop coating method onto a glassy carbon electrode (GCE) surface to build a sensor (nAu-Si4Pic~+Cl~-/GCE) which was used for the detection of o-nitrophenol (o-NP) and p-nitrophenol (p-NP). Under optimized experimental conditions the reduction peak current increased with increasing concentrations of both nitrophenol isomers in the range of 0.1-1.5 μmol L~(-1). The detection limits were 46 nmol L~(-1) and 55 nmol L~(-1) for o-NP and p-NP, respectively. These findings indicate that the nAu-Si4Pic~+Cl~- material is a very promising candidate to assemble electrochemical sensors for practical applications in the field of analytical chemistry.