Janjira PraneeradNichaphat ThongsaiPreeyanuch SupchocksoonthornSumana KladsomboonPeerasak PaoprasertMahidol UniversityThammasat University2020-01-272020-01-272019-03-15Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy. Vol.211, (2019), 59-70138614252-s2.0-85057465767https://repository.li.mahidol.ac.th/handle/20.500.14594/50575© 2018 Elsevier B.V. A recent trend in the preparation of carbon dots, optically unique nanomaterials, revolves around the use of readily-available, low-cost natural resources as precursors and their multipurpose applications. In this work, a hydrothermal method for preparing biocompatible carbon dots from radish was developed. The carbon dots were then tested for sensing of Cu 2+ and acetic acid vapor. The carbon dots exhibited blue emission under UV illumination with, a quantum yield of 15%. The fluorescence emission was selectively quenched when Cu 2+ ions were added, giving a detection limit of 0.16 μM. A paper-based fluorescent sensor was fabricated and shown to sense Cu 2+ with a limit of detection of 6.8 μM. The carbon dots were able to determine the Cu 2+ concentration in real water samples, with excellent recovery and reliability. The carbon dots were also used as the sensing material in an optical electronic nose, and tested for real-time detection of acetic acid vapor. Using principal component analysis, different ratios of acetic acid to methanol in solution were successfully identified with a detection limit of 15.5%. The acetic acid concentration in a real vinegar sample was also accurately determined. Our results demonstrated that label-free carbon dots derived from readily available radish can be simply used as versatile probes, giving them potential uses in multipurpose sensing applications.Mahidol UniversityChemistryArticleSCOPUS10.1016/j.saa.2018.11.049