Redox-Active Concanavalin A: Synthesis, Characterization, and Recognition-Driven Assembly of Interfacial Architectures for Bioelectronic Applications

DIEGO PALLAROLA; NURIA QUERALTO; WOLFGANG KNOLL; MARCELO CEOLÍN; OMAR AZZARONI; FERNANDO BATTAGLINI

LANGMUIR

AMER CHEMICAL SOC

Lugar: Washington; Año: 2010 vol. 26 p. 13684 - 13696

0743-7463

The convergence of chemistry, biology, and materials science has paved the way to the emergence of hybridnanobuilding blocks that incorporate the highly selective recognition properties of biomolecules, with the tailorablefunctional capabilities of inorganic molecules. In this work, we describe for the first time the decoration of concanavalinA (Con A), a protein with the ability to recognize sugars and form glycoconjugates, with Os(II) redox-active complexes.This strategy enabled the construction of electroactive biosupramolecular materials whose redox potentials could beeasily modulated through the facile molecular modification of the electroactive inorganic complexes. Small-angle X-rayscattering (SAXS), steady-state fluorescence, surface plasmon resonance (SPR) spectroscopy, matrix-assisted laserdesorption/ionization-time-of-flight mass spectrometry (MALDI-TOF-MS), and differential-pulsed (DPV) and cyclicvoltammetry (CV) were used to characterize the structural and functional features of the synthesized biohybrid buildingblocks as well as their respective supramolecular assemblies built up on gold electrodes. By harnessing the electroactiveand carbohydrate-recognition properties of these tailor-made biohybrid building blocks, we were able to integrateglucose oxidase (GOx) onto gold electrodes via sugar-lectin interactions. The redox activity of the Os-modified Con Ainterlayer allowed the electronic connection between the multilayered GOx assemblies and the metal electrode asevidenced by the well-defined bioelectrocatalytic response exhibited by the biomolecular assemblies in the presence ofthe glucose in solution. We consider that this approach based on the spontaneous formation of redox-activebiosupramolecular assemblies driven by recognition processes can be of practical relevance for the facile design ofbiosensors, as well as for the construction of new multifunctional bioelectrochemical systems.