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

Abstract 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.