A green emissive carbon-dot-based sensor with diverse responsive manners for multi-mode sensing. Issue 23 (25th October 2018) - Pan, Xiaohua
Abstract : Multi-mode sensing for Hg 2+, lemon yellow, H2 O2 and Fe 2+ achieved by a green emissive carbon-dot-based sensor with diverse responsive manners. Abstract : Since different quenching mechanisms can endow carbon dots (CDs) with diverse responsive manners, multi-mode sensing can in principle be achieved by a single carbon-dot-based sensor. In this work, green emissive CDs were prepared by simple hydrothermal pyrolysis of phenolphthalein and ethylenediamine at 180 °C for 5 h, with a quantum yield of 17%. The as-prepared CDs can be selectively quenched by Hg 2+ due to their specific binding affinity causing photo-induced electron transfer (PET). Due to the inner filter effect (IFE), the CDs also showed intensive fluorescent response to lemon yellow dye. Moreover, the CDs responded to Fe 2+ or H2 O2 selectively in the presence of H2 O2 or Fe 2+ owing to oxidative quenching (OQ) by hydroxyl radicals resulting from the Fenton reaction. Via the diverse responsive manners of PET, IFE and OQ, multi-mode sensing for Hg 2+, lemon yellow and Fe 2+, H2 O2 was thus achieved by a single green emissive carbon-dot-based sensor. Accordingly, the linear ranges for the selective detection of Hg 2+, lemon yellow, Fe 2+ and H2 O2 were found to be 0.0–500.0, 0.0–20.0, 0.0–90.0 and 0.0–50.0 μM, with the limits of detection as low as 5.8, 0.5, 1.2 and 1.1 μM, respectively.