We present a simple molecular approach to control the lipophilic/ hydrophilic nature of photoluminescent carbon dots (CDs) based on pyrolysis of alkyl gallate precursors. Depending on the gallic acid derivative used, CDs with different alkyl groups (methyl, propyl, lauryl) on the surface can be obtained by isothermal heating at 270 C. This precursor-derived approach allows not only the control of lipophilicity but also the length of the particular alkyl chain enables the control over both the size and photoluminescence (PL) of the prepared CDs. Moreover, the alkyl chains on the CDs surface can be readily converted to carboxylate groups via a mild base hydrolysis to obtain water dispersible CDs with a record biocompatibility. The observed differences in PL properties of CDs and time-resolved PL data, including contributions from carbogenic cores and surface functional group, are rationalized and discussed in detail using time-dependent density functional theory (TD-DFT) calculations. © 2013 Elsevier Ltd. All rights reserved.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): KUS-C1-018-02
Acknowledgements: The authors acknowledge the support by the Operational Program Research and Development for Innovations - European Regional Development Fund (CZ.1.05/2.1.00/03.0058 of the Ministry of Education, Youth and Sports of the Czech Republic) and Operational Program Education for Competitiveness - European Social Fund (CZ.1.07/2.3.00/20.0155 of the Ministry of Education, Youth and Sports of the Czech Republic). This work was also supported by the Grant Agency of the Czech Republic (P208/12/G016). Financial support from the Internal Student Grants (IGA) of Palacky University in Olomouc, Czech Republic, (PrF_2013_014 and PrF_2013_028) is also gratefully acknowledged. This publication is based on work supported in part by Award No. KUS-C1-018-02, made by King Abdullah University of Science and Technology (KAUST). We also thank A. Fargasova (Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacky University, Olomouc, Czech Republic) for Raman measurements and Z. Marusak (Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacky University, Olomouc, Czech Republic) for thermal analysis.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.