Abstract

Bio-Inspired Laser-Induced Electrochemical Sensing Strategies: Antigen/Nanobody-based Magnetosensing

Karolien De Wael, Professor, University of Antwerp

In my talk a sensing strategy inspired by the advantages of enzymes and photoelectrochemical sensing, namely the integration of aerobic photocatalysis and electrochemical analysis, will be presented. The photosensitizer, a bioinspired perfluorinated Zn phthalocyanine, generates singlet-oxygen from air under visible light illumination and oxidizes analytes, yielding electrochemically-detectable products while resisting the oxidizing species it produces. Compared with enzymatic detection methods, the proposed strategy uses air instead of internally added reactive reagents, features intrinsic baseline correction via on/off light switching and shows C-F bonds-type enhanced stability. It also affords selectivity imparted by the catalytic process and nano-level detection, such as 20nM amoxicillin in ml sample volumes.

Additionally, this strategy can be applied to improve the sensitivity of assays by using magnetic beads in combination with an amperometric readout in a configuration so-called electrochemical magnetosensor. The main difference between of a magnetosensor from a biosensor is that a biorecognition element is linked to magnetic beads and can be temporally dispersed in a sample for improving binding kinetics and, then, accumulated on an electrode by a magnet to register an analytical response. In comparison with conventional optical read-out systems, electrochemical sensors can register an analytical response almost immediately and without the need of developing the reaction in bulk volume, because the response of electrochemical sensors is determined by a thin layer of measuring solution near the electrode surface where the beads with immunoreagents are placed. This approach may improve sensitivity and decrease analysis time in comparison to conventional ELISA.