Conducting polymers with attached platinum nanoparticles towards the development of DNA biosensors

Based on the strong interaction of noble metal particles with the sulphur atoms of thiophene derivatives, platinum nanoparticles (Pt-NPs)-dispersed poly(3-methylthiophene) (P(3-MeTh)) thin films have been successfully prepared. Evidence of the Pt-NPs confinement in the polymer was provided by the electrocatalytic activity of the modified electrodes towards the dissolved oxygen reduction reaction. The efficient immobilization by self-assembly of thiolated oligonucleotides on the embedded Pt-NPs could be monitored by electrochemical quartz crystal microbalance (EQCM) as well as the subsequent hybridization with the complementary sequence. The good conducting properties and high surface area of P(3-MeTh)/Pt-NPs modified electrodes also allowed the detection of both processes by cyclic voltammetry.

► Preparation of P(3-MeTh)/Pt-NPs modified electrodes by spontaneous deposition of pre-synthesised nanoparticles.
► Electrocatalytic activity of P(3-MeTh)/Pt-NPs electrodes towards the ORR.
► Successfully immobilization of self-assembly of thiolated oligonucleotides on the P(3-MeTh)/Pt-NPs electrodes.
► Monitorization of thiolated oligonucleotides self-assembly and hybridization with the complementary sequence, by EQCM.