Boronic acid substituted viologen based optical sugar sensors: modulated quenching with viologen as a method for monosaccharide detection

In our search for an optical glucose sensor we have found that the combination of pyranine 1 and a boronic acid substituted benzyl viologen (o-BBV, 2) signals monosaccharides in the range of 0–1800 mg/dL. The quenching ability of o-BBV is modulated upon sugar binding, which in turn alters the fluorescence of pyranine. The system utilizes a dye that is active in the visible spectrum, operates in aqueous solution at pH 7.4, and is highly sensitive to glucose in the physiological range.