Towards Electrochemically-induced Autocatalysis for Signal Amplification

Abstract

Redox cross-catalysis is an autocatalytic reaction scheme that provides exponential molecular amplification, with potential applications in signal amplification for bioanalysis. It consists on the coupling between two catalytic processes in a product-to-catalyst relationship.1 We recently developed such a reaction scheme on the basis of the oxidative cleavage of boronate probes and the redox chemistry of quinones in the presence of reducing species and molecular oxygen.2,3,4 More specifically, our system consists in a cross-catalysis between the H2O2-mediated catalytic deprotection of a masked quinone and the catalytic production of H2O2 by a quinone-based redox cycling. It will be shown how the quinone masking strategy can result in a highly reactive and/or highly stable co-reactant, notably by introducing a double masking strategy.2

Then, by introducing an electrochemical quinone reduction to this system, we derived the original concept of electrochemically driven molecular autocatalysis, in which the molecular redox-active catalyst of an electrochemical reaction positively feedbacks to activate itself. Depending on the kinetics of the system, this self-activation process leads to highly nonlinear chronoamperograms, revealing the exponential nature of the molecular amplification. It will be shown that the success of the autocatalytic process results from the efficient coupling (through diffusion/reaction of the species) between the localized electrochemical reaction and the homogeneous feedback reaction. Therefore, this molecular amplification taking place in the vicinity of the electrode is very sensitive to hydrodynamic conditions. We will also discuss the importance of the choices to be made in the design of the electrochemical cell as well as in the nature of the working electrode if one wants to improve the kinetics and selectivity of this autocatalysis process.

References

[1] M. Branca, C. Calvet, B. Limoges, F. Mavré, ChemPhysChem, 22 (2021), 1611–21
[2] J. Pallu, C. Rabin, P. Hui, T. Moreira, G. Creste, C. Calvet, B. Limoges, F. Mavré and M. Branca, Chem. Sci, 13 (2022), 2764-77
[3] J. Pallu, C. Rabin, G. Creste, M. Branca, F. Mavré, B. Limoges, Chem. Eur. J., 25 (2019), 7534–46.
[4] P. Hui, M. Branca, B. Limoges, F. Mavré, Chem. Commun., 57 (2021), 11374-77


Biography

During his doctoral studies under the co-supervision of Professor Benoit Limoges and Professor Jean-Michel Savéant at the University of Paris Diderot, François Mavré developed the theory and practice of enzyme-modified electrodes to explore signal amplification strategies in biosensing electrochemical devices. He then spent two years in the Richard M. Crooks’lab at the University of Texas at Austin where he contributed to the development of bipolar electrochemistry in microsystems for its use for analytical purposes. François is now an assistant professor at the Department of Chemistry in Université de Paris. His researches mainly focus on electrochemistry-based methodologies to both investigate enzymatic reactivity/biomolecular interactions and develop non-linear amplification strategies in (electro-)analytical systems.