Fluorescence quenching-based bodipy-boronic acid linked viologen dual system for potential glucose sensing applications

Abstract

Purpose – The purpose of this study is to develop a non-enzymatic based glucose-sensing platform composed of Bodipy-BBV dual system which can be monitored by a photodetector under the blue LED excitation. Design/methodology/approach – The sensor has been developed from a dual system including a fluorescent dye, an aldehyde derivative of boron dipyrromethene (Bodipy) and a quencher, orto-boronic acid linked viologen (o-BBV) where their combination resulted in a ratiometric fluorescence quenching in ethanol: PBS (1:1, pH:7.4) solution under UV light excitation. By glucose addition, o-BBV has been released from the Bodipy and binded to cis-diol groups of glucose, thereby fluorescence emission of Bodipy has been regained. Furthermore, a setup consisting of a light emitting diode (LED) and a photodiode (PD) was used to prove electrical detection of glucose without the need for expensive and bulky optical equipment, enabling the development of a miniaturized and low-cost glucose-sensing platform. Findings – The fluorescence intensity of the Bodipy derivative in the solution (2 106 M) was diminished by 93% in the presence of o-BBV solution (5 103 M). Upon the glucose addition, 81% of the Bodipy fluorescence intensity has been recovered after introduction of 30 mM of glucose, where the ratio of o-BBV/Bodipy was 35:1. A linear response between 10 and 30 mM glucose concentration was obtained, which covers the biologically significant range. A high correlation between the photodiode current and Bodipy fluorescence intensity was achieved. Originality/value – Even though Bodipy molecules are known with their superior optical properties and applied to the fluorescence-based detection of glucose, to the best of the authors’ knowledge, no work has been reported on Bodipy-BBV dual system to detect glucose molecules as a nonenzymatic based method. This design enables the dye and the quencher to independently coexist in the solution, allowing for tuning of their individual concentrations to optimize the glucose sensitivity. Furthermore, an electrical light detection scheme consisting of a LED and a photodiode has been implemented to eliminate the bulky optical equipment from the measurement setup and further this work for the development of a compact and inexpensive sensor. The results presented here demonstrate the feasibility of this system for the development of a novel glucose sensor.