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.com
Volume 7
Biosensors Journal
ISSN: 2090-4967
Electrochemistry 2018
June 11-12, 2018
June 11-12, 2018 | Rome, Italy
4
th
International Conference on
Electrochemistry
Electrochemical regulation of the acidity in miniaturized electrochemical cells: The route to increase
flexibility and multiplexing of chemical control
César Pascual García
1
, Wouter Olthuis
2
and
Divya Balakrishnan
1, 2
1
Luxembourg Institute of Science and Technology, Luxembourg
2
MESA+ Institute - University of Twente, Netherlands
B
etter computer controlled systems to perform nanoscale chemical tasks is a demand for the fabrication of high-throughput
microarrays and reprogrammable sensors dedicated to precision personalized medicine. The very limited tools that
we have today to control chemical reactions in miniaturized devices is one of the main barriers for the control of massive
multiplexing (>1 Mega spots). The proton concentration is one of the building blocks that could be used to control the kinetics
of chemical reactions. Currently the multiplexed systems for high-yield
in-situ
synthesis of commercial microarrays are driven
by optically triggered acid-labile groups. The electrochemical control of the proton release would be a natural way to control
the acidity due to the high speed efficiency of redox processes, and would allow combining microarrays and programmable
electrochemical sensors. However, only a couple of attempts can be found in literature to control chemical reactions in
miniaturized environments by an electrochemically driven proton concentration. The limited surface to volume ratio of the
electrodes and the fast diffusion of protons decreased the performance of these systems. Here we present our studies to control
reversibility of redox processes that can be used to change the pH in microfluidic environments during many cycles, and a
microfluidic design to control the fast diffusion of protons. With our system we show a pH swing comparable to the highest
achieved by electrochemical systems of few milliliters, but in a device where the acid is confined in nano-litter volumes. The
design promises high yield
in-situ
chemical synthesis since the system is compatible with lateral resolutions in the micron
range assuring the stability of acid contrast between close spots.
Figure 1: A)
Chip with nano-litter reaction cells. B) Schematic representation of the acid control in the nano-fluidic reactor.
C) CV of proton exchange reactions driven by Amino-thiol-phenol. D) Evolution of the pH dependent fluorescence in one of the cycles.
Recent Publications
1. A Courbet, E Renard and F Molina (2016) Bringing next-generation diagnostics to the clinic through synthetic biology.
EMBO Mol. Med. 8(9):987.
2. K Maurer, J Cooper, M Caraballo, J Crye, D Suciu, A Ghindilis, J A Leonetti, WWang, F M Rossi, A G Stöver, C Larson,
H Gao, K Dill and A McShea (2006) Electrochemically generated acid and its containment to 100 micron reaction areas
for the production of DNA microarrays. PLoS ONE 1(1):e34.
3. Wang Y C, Lin C B, Su J J, Ru Y M, Wu Q, Chen Z B, Mao B W and Tian Z W (2011) Electrochemically driven large
amplitude pH cycling for acid-base driven DNA denaturation and renaturation. Anal. Chem. 83:4930.
4. D Balakrishnan, G Lamblin, J S Thomann, J Guillot, D Duday, A van den Berg, W Olthuis and C Pascual Garcia (2017)
Influence of polymerization on the reversibility of low-energy proton exchange reactions by para-aminothiolphenol.
Scientific Reports 7(1):15401.
5. Balakrishnan D, Lamblin G, Thomann J S, van den Berg A, Olthuis W and Pascual Garcia C (2018) Electrochemical
control of pH in nano-liter volumes. Nano Lett. 18(5):2807-2815.
César Pascual García et al., Biosens J 2018, Volume 7
DOI: 10.4172/2090-4967-C1-002