Multifunctional Electrode Arrays: Towards a Universal Detection Platform

Abstract

In this article we review recent work in our laboratory towards the realization of a multianalyte microelectrode detection platform capable of discriminating chemicals and different biomolecules simultaneously. The functionalization of electrodes with aryl diazonium salts provides an electrically addressable deposition procedure capable of immobilizing a wide range of molecules. We demonstrate control over surface density and electron transfer kinetics as well as the activation of individual electrodes in an array. The direct electrically-addressable immobilization of diazonium-modified proteins is shown to be suitable for the construction of multianalyte immunosensors and the immobilization of horseradish peroxidase leading to the direct electron transfer between the redox enzyme and the electrode. The use of catalytic nanoparticles leads to the construction of a reagent-less immunosensor and the simultaneous detection of DNA and proteins on the same electrode array is demonstrated.

Electrochemical properties of aryl-modified gold electrodes

“…Stronger inhibition was observed, however, by increasing the grafting time at a constant potential [23,36]. By contrast, Liu et al observed that a CP film of submonolayer coverage suppressed electron transfer compared with bare gold [27].…”

Covalent Modification of Glassy Carbon Surfaces by Using Electrochemical and Solid‐Phase Synthetic Methodologies: Application to Bi‐ and Trifunctionalisation with Different Redox Centres

“…[27,[35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50] The main strategy consists of immobilising a 4-nitrophenyl group at the carbon surface by reducing the corresponding diazonium salt, reducing the nitro group to an amine group, then allowing subsequent chemical modifications. [27,35,36,41,43,48,50] Other examples include the immobilisation of a 4-carboxyphenyl group, [39,42,46,47] 4-(chloromethyl)phenyl group, [37,38] 4-(aminoethyl)phenyl group, [40] and more recently phenylmaleimide group, [44] phenylazide or phenylacetylene groups, [45] and boronic acid group, [49] followed by further chemical modification at the reactive groups for the preparation of single modified carbon A C H T U N G T R E N N U N G electrodes.…”

Electronic Tongues Employing Electrochemical Sensors

“…In this way, arrays of DNA, antibodies, enzymes, and peptides can be selectively immobilized, aiming to different multiplex biosensing schemes. For examples, a protein and a DNA fragment can perform as a double confirmation test for presence of bioterrorism threats; or the double detection of a gene mutation and a tumor protein marker may confirm a specific malignant growth [104]. The multiplex biosensing concept was implemented with an impedimetric DNA biosensing scheme [105].…”