Nanoarchitectures based on multi-walled carbon nanotubes non-covalently functionalized with Concanavalin A: A new building-block with supramolecular recognition properties for the development of electrochemical biosensors

ORTIZ, ELVIS; GALLAY, PABLO; GALICIA, LAURA; EGUÍLAZ, MARCOS; RIVAS, GUSTAVO

SENSORS AND ACTUATORS B-CHEMICAL

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 2019 vol. 292 p. 254 - 262

0925-4005

We propose an innovative nanoarchitecture for the development ofelectrochemical biosensors based on the non-covalent functionalization of multiwalled carbon nanotubes (MWCNTs) with the lectin Concanavalin A (ConA) andthe site-specific supramolecular binding of glycobiomolecules. As proof-ofconcept, we propose the use of two glycoenzymes, glucose oxidase (GOx) andhorseradish peroxidase (HRP), for building mono- and bienzymatic glucosebiosensors. The selected conditions for the preparation of the dispersion were1.5 mg MWCNTs in 1.0 mL of 2.0 mg mL-1 ConA sonicated for 5.0 min withsonicator probe. The monoenzymatic glucose biosensor was prepared by castingGCE with the MWCNTs-ConA dispersion (GCE/MWCNTs-ConA) followed by theinteraction with GOx (GCE/MWCNTs-ConA/GOx), while the bienzymatic one wasobtained by interaction of GCE/MWCNTs-ConA with GOx + HRP(GCE/MWCNTs-ConA/GOx-HRP). The best analytical performance wasobtained with the bienzymatic biosensor from the amperometric response at -0.050 V in the presence of 1.0 x 10-4 M hydroquinone. The sensitivity was (2.22± 0.03) μA mM-1(which was 5.2 times higher than the one obtained with themonoenzymatic biosensor) and a detection limit of 0.31 μM. The reproducibilitywas 5.4 % and the biosensor was challenged with human blood serum showingan excellent correlation with the values reported by the laboratory.