Carbon Dots: A Modular Activity To Teach Fluorescence and Nanotechnology at Multiple Levels

• Published in: Journal of chemical education Vol. 94; no. 8; pp. 1143 - 1149
• Main Authors: Pham, Susan N, Kuether, Joshua E, Gallagher, Miranda J, Hernandez, Rodrigo Tapia, Williams, Denise N, Zhi, Bo, Mensch, Arielle C, Hamers, Robert J, Rosenzweig, Zeev, Fairbrother, Howard, Krause, Miriam O.P, Feng, Z. Vivian, Haynes, Christy L
• Format: Journal Article
• Language: English
• Published: Easton American Chemical Society and Division of Chemical Education, Inc 08.08.2017; Division of Chemical Education, Inc and ACS Publications Division of the American Chemical Society; American Chemical Society
• Subjects: Atomic force microscopy; Carbon; Carbon dots; Chemistry; College Science; College students; Colleges & universities; Consumer products; Crosslinking; Division; Educational attainment; Electron microscopy; Electronic Equipment; Emission analysis; Emission spectra; Ethylenediamine; Fluorescence; Function words; Image transmission; Laboratories; Laboratory Equipment; Laboratory Experiments; Light; Molecular Structure; Morphology; Nanomaterials; Nanoparticles; Nanotechnology; Organic Chemistry; Particle physics; Quantum dots; Science Activities; Science Curriculum; Science Instruction; Science Laboratories; Secondary School Science; Spectroscopy; Technology; Undergraduate Study; Upper Division Colleges; First-Year Undergraduate/General; Hands-On Learning/Manipulatives; Upper-Division Undergraduate; Fluorescence Spectroscopy; Interdisciplinary/Multidisciplinary; High School/Introductory Chemistry; Environmental Chemistry; Nanotechnology
• ISSN: 0021-9584; 1938-1328
• DOI: 10.1021/acs.jchemed.6b00995

In recent years, nanomaterials have entered our daily lives via consumer products; thus, it has become increasingly important to implement activities to introduce these novel materials into chemistry curricula. Here we introduce a newly developed fluorescent nanomaterial, carbon dots, as a more environmentally friendly alternative to heavy-metal semiconductor quantum dots to be used as a model nanomaterial for experiments at multiple educational levels ranging from high school to upper-division college laboratories. These dots, which are polymeric in nature, can be made from a variety of carbon precursors and a cross-linker such as ethylenediamine. The synthesis, which involves heating in a conventional microwave, is quick and straightforward and can be carried out in typical high school chemistry laboratories. The resulting solution is fluorescent without further purification. To increase the complexity for entry-level college students, absorption and emission spectra of the carbon dot solution can be collected as an introduction to spectroscopy. In more advanced undergraduate lab courses, the quantum yield can be determined with a standard reference fluorescent material such as quinine sulfate. Atomic force microscopy or transmission electron microscopy images can also be collected to illustrate the morphology of these particles where such specialty instruments are accessible.