A rhodamine-nitronaphthalimide Hg(II) complex for the simultaneous detection of oxidised and reduced glutathione

• Published in: Sensors and actuators. B, Chemical Vol. 300; p. 126825
• Main Authors: Sharma, Hemant, White, Jonathan M., Lin, Jiarun, New, Elizabeth J., Pfeffer, Frederick M.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.12.2019; Elsevier Science Ltd
• Subjects: Chemosensors; Fluorescence; Glutathione; Logic circuits; Mercury (metal); Mercury compounds; Naphthalimide; Rayleigh scattering; Resonance scattering; Rhodamine; Fluorescence; Rhodamine; Naphthalimide; Chemosensors; Glutathione
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2019.126825

The Hg(II) complex of rhodamine-nitronaphthalimide 1 can sense and discriminate both the oxidised and reduced forms of glutathione (GSSG and GSH). [Display omitted] •The unique crystal structure of 1 shows coplanar chromophores—energy transfer processes such as FRET can readily occur.•The 1:Hg complex gives a unique fluorescent response for both forms of the biologically relevant glutathione (GSH and GSSG).•Cellular imaging shows that 1 readily crosses cell membranes and has potential use in evaluating biochemical redox processes. Dual-fluorophore systems have attracted attention as they offer versatile photophysical properties and multiple mechanisms for sensing. Here we report that the Hg2+ complex of rhodamine-nitronaphthalimide conjugate 1 functions as a switch-on sensor for the simultaneous detection of reduced (GSH) and oxidised (GSSG) glutathione via a resonance Rayleigh scattering process, with detection limits of 4.3 μM and 11.9 μM, respectively. Hydroxide anion regenerates nitronanphthalimide 1 causing the fluorescence to “switch-off”, and the system is recyclable. This photophysical behaviour towards Hg2+, GSH and HO‾ forms the basis of a molecular level INHIBIT and AND logic gate.