Synthesis of confined nanoparticles sensitive to small molecular conformational changes

ANA SOL PEINETTI; HELENA CERETTI; MARTIN MIZRAHI; GRACIELA A. GONZÁLEZ; SILVANA A. RAMÍREZ; FELIX G. REQUEJO; JAVIER M. MONTSERRAT; FERNANDO BATTAGLINI

York

Conferencia; 12th International Conference on Materials Chemistry; 2015

Royal Society of Chemistry

The synthesis of metal nanoparticles by pulsed galvanostatic electrodeposition on nanoporous alumina is presented. The method allows the production of different metal nanoparticles (Au, Pt, Ni) with active uncapped surface that present an excellent electron transfer process and can be easily modified. The NPs size can be controlled through the nanoporous diameter, obtaining particles from 1 to 10nm (Table 1). The alumina structure was characterised by SEM images and the size and modification of the generated NPs were determined in-situ by extended x-ray absorption fine structure (EXAFS).This strategy represents a simple and efficient method for the construction of nanometre electrode arrays exemplified here by the electrochemical response of different species(ferrocyanide, hexaammineruthenium, methylene blue).As model system, gold nanoparticles electrogenerated in the alumina cavities with a controlled size (2 nm) are easily modified with a thiol-containing aptamer for the label-free detection of small molecules by electrochemical impedance spectroscopy (Figure 1). Our results show that the use of a limited electrical conducting surface inside an insulating environment can be very sensitive to aptamers conformational changes, introducing a new approach to the detection of small molecules exemplified here by the direct and selective detection of adenosine monophosphate at nanomolar concentrations.This work demonstrated the advantages of a novel nanometer scale architecture for signal enhancing.