Green route for synthesis of multifunctional fluorescent carbon dots from Tulsi leaves and its application as Cr(VI) sensors, bio-imaging and patterning agents

• Published in: Colloids and surfaces, B, Biointerfaces Vol. 167; pp. 126 - 133
• Main Authors: Bhatt, Shreya, Bhatt, Madhuri, Kumar, Anshu, Vyas, Gaurav, Gajaria, Tejal, Paul, Parimal
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-07-2018
• Subjects: Carbon dots; Chromium (VI); Imaging; Inner filter effect; Patterning; Real sample analysis; Patterning; Inner filter effect; Real sample analysis; Carbon dots; Chromium (VI); Imaging
• ISSN: 0927-7765; 1873-4367
• DOI: 10.1016/j.colsurfb.2018.04.008

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•Carbon dots were prepared from Tulsi leaves by one step hydrothermal process.•These carbon dots are used as potential sensor for Cr(VI) in aqueous media.•The detection of Cr(VI) is based on a mechanism called inner filter effect (IFE).•These CDs are low toxic and used as excellent imaging and patterning agent.•CDs were successfully used for detection of Cr(VI) in tap and industrial water.
We report a one pot green strategy for the synthesis of carbon dots using tulsi leaves and their potential application in sensing of Cr(VI) selectively. The detection mechanism is based on the phenomenon called inner filter effect (IFE) and a good linear static quenching was observed in the range of 1.6 μM to 50 μM with a detection limit of 4.5 ppb. The reversible switching in fluorescence has been tested and a good recovery in fluorescence was observed up to three consecutive cycles upon addition of ascorbic acid as reducing agent. Also the low toxicity, high fluorescence and photostabilty of the CDs make them excellent imaging and patterning agent. The acid and alkali resistant property of these CDs makes it suitable for real sample analysis. The fluorescent CDs were applied for successful detection of Cr(VI) in water with spike-recoveries ranging from 93 to 99%.