Dual Enzymatic Detection by Bulk Electrogenerated Chemiluminescence

Abstract

The combination of enzymes, as recognition elements for specific analytes, and of electrogenerated chemiluminescence (ECL) as a readout method has proven to be a valuable strategy for sensitive and specific analytical detection. However, ECL is intrinsically a 2D process which could potentially limit the analysis of inhomogeneous samples. Here, we show how a bulk ECL signal, generated by thousands of carbon microbeads remotely addressed via bipolar electrochemistry, are implemented as a powerful tool for the concomitant ECL sensing and imaging of two enzymatic substrates. We selected two enzymes (glucose dehydrogenase and choline oxidase) that react with their respective model substrates and produce in situ chemical species (β-nicotinamide adenine dinucleotide (NADH) and H2O2) acting as coreactants for the ECL emission of different luminophores ([Ru(bpy)3](2+) at λ = 620 nm and luminol at λ = 425 nm, respectively). Both enzymes are spatially separated in the same capillary. We demonstrate thus the simultaneous quantitative determination of both glucose and choline over a wide concentration range. The originality of this remote approach is to provide a global chemical view through one single ECL image of inhomogeneous samples such as a biochemical concentration gradient in a capillary configuration. Finally, we report the first proof-of-concept of dual biosensing based on this bulk ECL method for the simultaneous imaging of both enzymatic analytes at distinct wavelengths.

Tracking Magnetic Rotating Objects by Bipolar Electrochemiluminescence

“…This contactless feature of BPE, which constitutes an essential advantage in comparison to classic electrochemistry, has been recently exploited to address either single objects or large ensembles comprising thousands or millions of objects simultaneously with just two feeder electrodes. [18][19][20][21] BPE has been also applied to activate other functions such as light-emitting processes, especially electrochemiluminescence (ECL). [22][23][24][25] ECL is an ultrasensitive and powerful method triggered by an initial electrochemical step.…”

Wireless Addressing of Freestanding MoSe2 Macro- and Microparticles by Bipolar Electrochemistry

“…40 Also, the miniaturization of the bipolar electrode together with the simultaneous addressing of a large number of particles was proposed. 28,41 The advantage of this approach is to allow the BPEpromoted electron transfer, which is usually confined to the electrode surface (i.e. 2D), to occur in the bulk of a solution (3D).…”

Capillary‐assisted bipolar electrochemistry: A focused mini review

“…This opens the door to multianalyte detection, which was demonstrated with two enzymatic systems for the detection of two biorelevant substrates, namely glucose and choline, by using simultaneously two enzymes (Fig. C) . For that purpose, a dehydrogenase and an oxidase were used, respectively.…”