Amperometric aptasensor for carcinoembryonic antigen based on the use of bifunctionalized Janus nanoparticles as biorecognition-signaling element

PANIAGUA, GONZALO; VILLALONGA, ANABEL; EGUÍLAZ, MARCOS; VEGAS, BORJA; PARRADO, CONCEPCIÓN; RIVAS, GUSTAVO; DÍEZ, PAULA; VILLALONGA, REYNALDO

ANALYTICA CHIMICA ACTA

ELSEVIER SCIENCE BV

Año: 2019 vol. 1061 p. 84 - 84

0003-2670

e report herein the design of a novel biosensing strategy for the detection of carcinoembryonic antigen (CEA), based on the use of Janus-type nanoparticles having Au and silica opposite faces as integrated electrochemical biorecognition-signaling system. The Janus nanoparticles were properly functionalized with horseradish peroxidase on the silica surface to act as signaling element, and a biotin thiol-modified anti-CEA DNA hairpin aptamer the Au face to assemble the biorecognition element. The sensing approach relies on the first specific recognition of CEA by the bifunctionalized Janus nanoparticles, causing unfolding of the DNA hairpin structure and unmasking the biotin residues at the aptamer chain. This CEA-Janus nanoparticle complex was then captured by avidin-modified Fe 3 O 4 @SiO 2 NanoCaptors ® , allowing further magnetic deposition on carbon screen printed electrodes for the amperometric detection of the cancer biomarker. The Janus nanoparticles-based aptasensor was able to