Bioengineering a glucose oxidase nanosensor for near-infrared continuous glucose monitoring†

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Zubkovs, Vitalijs
Wang, Hanxuan
Schuergers, Nils
Weninger, Astrid
Glieder, Anton
Cattaneo, Stefano
Boghossian, Ardemis A.
"Single-walled carbon nanotubes (SWCNTs) emit photostable near-infrared (NIR) fluorescence that is conducive for optical glucose monitoring. Such SWCNT-based optical sensors often require the immobilization of proteins that can confer glucose selectivity and reactivity. In this work{,} we immobilize a glucose-reactive enzyme{,} glucose oxidase (GOx){,} onto SWCNTs using a N-(1-pyrenyl)maleimide (PM) crosslinker via thiol bioconjugation of engineered cysteine residues. We compare the conjugation of several glucose oxidase variants containing rationally-engineered cysteines and identify a D70C variant that shows effective bioconjugation. The bioconjugation was characterized through both absorption and fluorescence spectroscopy. Furthermore{,} we demonstrate an application for continuous glucose monitoring in the NIR-II optical region using the bioconjugated reaction solution{,} which shows a reversible response to physiological concentrations of glucose. Finally{,} we develop a miniaturized NIR-II reader to be used for cell cultures that require continuous glucose monitoring."
Publication Reference
Nanoscale Advances, 2022