INVESTIGADORES
PAZ ZANINI Veronica Irene
artículos
Título:
A highly sensitive and stable glucose biosensor using thymine-based polycations into laponite hydrogel films
Autor/es:
VERONICA I PAZ ZANINI; MAXIMILIANO GAVILAN; BEATRIZ A LÓPEZ DE MISHIMA; DEBORA M MARTINO; CLAUDIO D. BORSARELLI
Revista:
TALANTA
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2016 vol. 150 p. 646 - 654
ISSN:
0039-9140
Resumen:
A series of glucosebioelectrodes were prepared by glucose oxidase (GOx) immobilization into laponitehydrogel films containing DNA bioinspired polycations made of vinylbenzyl thymine (VBT) andvinylbenzyl triethylammonium chloride (VBA) with general formulae [(VBT)m(VBA)n]n+ with m = 0, 1 and n = 2, 4 and 8, deposited onto glassy carbon electrode. The bioelectrodes were characterized bychronoamperometry, cyclic voltammetry and electrochemical impedancespectroscopy. Results indicated that the electrochemical properties of thelaponite hydrogel films were largely improved by the incorporation of thymine-basedpolycations, being proportional to the positive charge density of the polycationmolecule. After incorporation of glucose oxidase, the sensitivity of thebioelectrode to glucose increased with the positive charge density of thepolycation. Additionally, the presence of the vinylbenzyl thymine moiety playeda role in the long-term stability and reproducibility of the bioelectrodesignal. As a consequence, the [(VBT)m(VBA)n]n+ was the mostappropriate polycation for bioelectrode preparation and glucose sensing, with aspecific sensitivity of se = 176 mA mmol-1L cm-2 U-1,almost two-order of magnitude larger than other laponite immobilized GOxbioelectrodes reported elsewhere.Thesefeatures were confirmed by testing the bioelectrodefor a selective determination of glucose in powder milk and blood serum sampleswithout interference of either ascorbic or uric acids under the experimentalconditions.Thepresent study demonstrates the suitability of DNA bioinspired water-soluble polycations [(VBT)m(VBA)n]n+ for enzymeimmobilization like GOx into laponitehydrogels and the preparation of highly sensitive and stable bioelectrodes onglassy carbon surface.
