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

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

Nanoscale

Royal Society of Chemistry

Año: 2015 vol. 7 p. 7763 - 7769

2040-3364

A controlled architecture of nanoelectrodes, of a similar size to small molecule-binding aptamers, is synthesized inside nanoporous alumina. Gold nanoparticles with a controlled size (about 2 nm) are electrogenerated in the alumina cavities, showing a fast electron transfer process toward ferrocyanide. These uncapped nanoparticles are easily modified with a thiol-containing aptamer for 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 at the nanomolar scale.