title: Confined gold nanoparticles enhance the detection of small molecules in label-free impedance aptasensors.
abstract: 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.
authors.affiliation: INQUIMAE (CONICET) - Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, C1428EHA Buenos Aires, Argentina. battagli@qi.fcen.uba.ar.
authors.forename: Ana S
authors.initials: AS
authors.lastname: Peinetti
authors.forename: Helena
authors.initials: H
authors.lastname: Ceretti
authors.forename: Martín
authors.initials: M
authors.lastname: Mizrahi
authors.forename: Graciela A
authors.initials: GA
authors.lastname: González
authors.forename: Silvana A
authors.initials: SA
authors.lastname: Ramírez
authors.forename: Felix G
authors.initials: FG
authors.lastname: Requejo
authors.forename: Javier M
authors.initials: JM
authors.lastname: Montserrat
authors.forename: Fernando
authors.initials: F
authors.lastname: Battaglini
mesh_terms: D000249:Adenosine Monophosphate / Q000032:analysis; D000537:Aluminum Oxide / Q000737:chemistry; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D017097:Electric Impedance; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D016062:Porosity
chemical_list: D052157:Aptamers, Nucleotide; D000249:Adenosine Monophosphate; D006046:Gold; D000537:Aluminum Oxide