Novel fluorescence assay using µ-wells coated by BODIPY dye as an enzymatic sensing platform

Abstract

BODIPY dyes are strongly fluorescent small molecules widely used in fluorescence sensing various analytes. In this study, 8-chloromethyl-2,6-diethyl-4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene (BODIPY-CH2Cl) was successfully synthesized and used as a sensing platform in a 96-well microplate. After synthesis, commercial 96-well microplate surfaces covered with Poly-D-Lysine layer were modified with BODIPY. Glucose oxidase (GOx) was selected as a model enzyme to test the applicability of the BODIPY-coated surface as a fluorescence sensing platform. Since oxygen acts as a quencher for BODIPY, the addition of substrate to modified surfaces caused oxygen depletion and resulted in a quick increase fluorescence intensity. The increments were in proportion to the glucose concentration. Using these data, a linear graph was obtained between 0.0025 and 0.1 mM glucose with a LOD of 2.19 µM. There was no interference effect of some compounds, such as uric acid, ascorbic acid, phenols, and ethanol on sensing. Glucose detection in various complex matrices was carried out. © 2018 Elsevier Ltd