Green synthesis of carbon nanodots from cotton for multicolor imaging, patterning, and sensing

An extreme green and economical strategy for producing fluorescent carbon nanodots (CDs) by pyrolysis and microwave treatment of cotton is proposed for the first time. The fabricated CDs exhibit exceptional advantages including high fluorescent quantum yield, excellent biocompatibility, low-toxicity, and satisfactory chemical stability. Depending on these superior properties, the CDs have been applied in multicolor imaging, patterning, and sensing, respectively. According to the confocal fluorescent imaging of human uterine cervical squamous cell carcinoma cells, the CDs can penetrate into the cell and enter the cytoplasm and nucleus, suggesting pleasurable promise for bioimaging. Additionally, the obtained CDs have been used as fluorescent inks for drawing luminescent patterns, showing favorable application in anti-counterfeit and optoelectronic dimensions. Most strikingly, the as-prepared CDs can sensitively and selectively 'detect Fe3+ ions in a linear range of 5.0 x 10(-8)-1.0 x 10(-5) M with a detection limit as low as 2.7 x 10(-8) M. (C) 2015 Elsevier B.V. All rights reserved.