Confined Gold Nanoparticles Enhance the Detection of Small Molecules in Label-Free Impedance Aptasensors

ANA SOL PEINETTI; HELENA CERETTI; MARTÍN MIZRAHI; GONZALEZ GRACIELA ALICIA; SILVANA RAMIREZ; FELIX REQUEJO; JAVIER M. MONSERRAT; FERNANDO BATTAGLINI

Nanoscale

Royal Society of Chemistry.

Año: 2015 p. 7763 - 7769

2040-3364

Abstract A controlled architecture of nanoelectrodes, with a similar size to small molecule-binding aptamers, is synthetized inside nanoporous alumina. Gold nanoparticles are electrogenerated in the alumina cavities with a controlled size (2 nm), showing a fast electron transfer process toward ferrrocyanide. These caped-free nanoparticles are easily modified with a thiol-containing aptamer for the label-free detection of adenosine monophosphate by electrochemical impedance spectroscopy. Our results show that the use of a limited electrical conducting surface inside an insulating environment can be very sensitive to conformational changes, introducing a new approach to the detection of small molecules exemplified here by the direct and selective detection of adenosine monophosphate in the nanomolar scale.