Synthesis of confined nanoparticles sensitive to small molecular conformational changes

PEINETTI, ANA S.*; CERETTI, HELENA; MIZRAHI, MARTÍN; GONZÁLEZ, GRACIELA A.; RAMÍREZ, SILVANA A.; REQUEJO, FELIX; MONTSERRAT, JAVIER M.; BATTAGLINI, FERNANDO

York

Conferencia; 12th International Conference on Materials Chemistry; 2015

Royal Society of Chemistry

The synthesis of metal nanoparticles by pulsedgalvanostatic electrodeposition on nanoporous alumina is presented. This methodallows the production of different metal nanoparticles (Au, Pt, Ni) with activeuncapped surface that present an highly efficient electron transfer process andcan be easily modified. The NPs size can be controlled through the nanoporousdiameter, obtaining particles from 1 to 10nm. The alumina structure wascharacterised by SEM images and the size and modification of the generated NPswere determined in-situ by extended X-ray absorption fine structure (EXAFS).This strategy represents a simple and efficient methodfor the construction of nanometre electrode arrays exemplified by the electrochemicalresponse of different species (ferrocyanide, hexaammineruthenium, methyleneblue). As model system, gold nanoparticles electrogenerated inthe alumina cavities with a controlled size (2 nm) areeasily modified with a thiol-containing aptamer for the label-free detection ofsmall molecules by electrochemical impedance spectroscopy. Our results showthat the use of a limited electrical conducting surface inside an insulatingenvironment can be very sensitive to aptamers conformational changes,introducing a new approach to the detection of small molecules exemplified hereby the direct and selective detection of adenosine monophosphate at nanomolarconcentrations.Thiswork clearly shows the advantages of a novel nanometre scale architecture forsignal enhancing.