Facile green synthesis of carbon dots from Pyrus pyrifolia fruit for assaying of Al3+ ion via chelation enhanced fluorescence mechanism

In this work, we synthesized fluorescent carbon dots (CDs) using Pyrus pyrifolia (pear) fruit via hydrothermal method at 180 degrees C for 6 h without using any further treatment or surface passivating agents. The synthesized CDs possess intense blue fluorescence under UV lamp at 365 nm and exhibit emission peak at 471 nm when excited at 390 nm. Because of specific surface functional groups, the synthesized CDs showed high selectivity to detect Al3+ ion through chelation enhanced fluorescence (CHEF) mechanism. The emission peak intensity of CDs at 471 nm was gradually enhanced with increasing concentration of Al3+ ion, thereby Al3+ ion was quantified by plotting calibration curve over the range of 0.005-50 pM with a detection limit of 0.0025 pM (2.5 nM). The nanoprobe was subsequently evaluated by assaying Al3+ ion from spiked water samples, signifying the utility of nanoprobe for assaying of Al3+ ion real samples. Furthermore, we also demonstrate that the bioimaging ability of CDs for imaging of Bacillus subtilis bacterial cell, suggesting that the nanoprobe can be used for cell imaging applications. (C) 2018 Elsevier B.V. All rights reserved.