Fluorescence-surface enhanced Raman scattering dual-mode nanosensors to monitor hydroxyl radicals in living cells

Abstract

Hydroxyl radicals (OH) play significant roles in physiological and pathological processes, thus, the development of a highly sensitive and selective detection method for OH in living cells is important to evaluate its biological roles. In this work, novel fluorescence-surface enhanced Raman scattering (fluorescence-SERS) dual-mode nanosensors were explored to detect OH in living cells with high selectivity and accuracy. The strategy was based on the “on-off” switch of fluorescence resonance energy transfer (FRET) and SERS signals, which was triggered via the OH-induced cleavage of DNA strands. The results suggested that the fluorescence-SERS nanosensors exhibited excellent selectivity for OH over other related biological species, and high sensitivity with a limit of detection of 10nM, which fulfill the requirements for detection of OH in biological systems. The present nanosensors were successfully incubated in living cells and used to monitor OH levels under oxidative stress, which holds great promise for the in situ investigation of pathophysiological processes in biological systems involving hydroxyl radicals.