Modified porous silicon for electrochemical sensor of para-nitrophenol

• Hybrid device based on Porous silicon (PSi) and polythiophene (PTh) was prepared.
• Three types of PSi/PTh hybrid structures were elaborated: PSi/PTh, oxide/PSi/PTh and Amino-propyltrimethoxysilane (APTMES)/oxide/PSi/PTh.
• PTh was grafted on PSi using electrochemical polymerization.
• The electrodetection of para-nitrophenol (p-NPh) was performed by cyclic voltammetry.
• Oxide/PSi/PTh and APTMES/oxide/PSi/PTh, based electrochemical sensor showed a good response toward p-NPh.

Hybrid structures based on polythiophene modified porous silicon was used for the electrochemical detection of para-nitrophenol, which is a toxic derivative of parathion insecticide and it is considered as a major toxic pollutant.The porous silicon was prepared by anodic etching in hydrofluodic acid. Polythiophene films were then grown by electropolymerisation of thiophene monomer on three different surfaces: hydrogenated PSi, oxidized PSi and amine-terminated PSi.The morphology of the obtained structures were observed by scanning electron microscopy and characterized by spectroscopy (FTIR). Cyclic voltammetry was used to study the electrochemical response of proposed structures to para-nitrophenol. The results show a high sensitivity of the sensor and a linearity of the electrochemical response in a large concentration interval ranging from 1.5 × 10−8 M to the 3 × 10−4M.