Naked oats-derived dual-emission carbon nanodots for ratiometric sensing and cellular imaging

We report a green and facile strategy for fabrication of dual-emission carbon nanodots (CDs), and demonstrate their applications in ratiometric sensing and cellular imaging. Dual-emission CDs have been prepared by pyrolysis and microwave treatment of naked oats, providing a novel way for the production of dual luminance CDs without the request of tedious synthetic methodology or the use of toxic/expensive solvents and starting materials. Their intriguing dual fluorescence behavior is observed when the excitation wavelength is between 250 and 310 nm. The well-resolved dual emission bands manifest excitation and temperature dependence. The obtained CDs were applied as a ratiometric fluorescent sensing platform for precise and quantitative detection of Al3+ ions and pH values, and as optical nanoprobes for cellular imaging. (C) 2014 Elsevier B.V. All rights reserved.