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 AuCl4− ions allowed well-dispersed nAu to be obtained with an average particle size of 4.5nm. 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 0.1–1.5μmolL−1. The detection limits were 46nmolL−1 and 55nmolL−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.