REDUCED GRAPHENE OXIDE AND Tb-DO3A CONJUGATE AS LUMINESCENT CHEMOSENSOR FOR AGILE DETECTION OF HYDROXYL RADICAL

The development of chemosensors for the detection of hydroxyl radicals (HO•) is a challenging task since HO• has an exceptionally short lifetime (in vivo half-life of 1 ns). In this work, we have designed and synthesized a versatile probe, viz. Tb@rGO, for the detection of HO• amongst the biologically important ions and reactive oxygen species (ROS). Our design is based on covalent conjugation of reduced graphene oxide (rGO) with terbium (III)-1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid (Tb-DO3A). Tb@rGO is characterized by traditional spectroscopic methods including XRD, SEM, TEM, and zeta potential analysis. Furthermore, we elaborate the photophysical properties of Tb@rGO. Accordingly, our results attest that Tb@rGO has unique luminescence features, rendering it highly effective in the detection of HO•. Remarkably, Tb@rGO is highly selective to HO• among many biologically important species in 0.1 M pH 7.4 phosphate buffered saline solution. It is also noteworthy that the limit of detection (LOD) is 0.92 M for HO•. Therefore, this novel material hold promises as selective turn-off luminescent HO• probe.