Diana M A Crista1, Abderrahim El Mragui1, Manuel Algarra2, Joaquim C G Esteves da Silva1,3, Rafael Luque4,5, Luís Pinto da Silva1,3. 1. Chemistry Research Unit (CIQUP), Faculty of Sciences of University of Porto, R. Campo Alegre 697, 4169-007 Porto, Portugal. 2. Department of Inorganic Chemistry, Faculty of Science, University of Málaga, Campus de Teatino s/n, 29071 Málaga, Spain. 3. LACOMEPHI, GreenUPorto, Department of Geosciences, Environment and Territorial Planning, Faculty of Sciences of University of Porto, R. Campo Alegre 697, 4169-007 Porto, Portugal. 4. Departamento de Química Orgánica, Universidad de Córdoba, Edif. Marie Curie, Ctra N-IVA Km 396, E-14014 Córdoba, Spain. 5. Center for Molecular Design and Synthesis of Innovative compounds for Medicine, Peoples Friendship University of Russia (RUDN University), 6 Miklukho Maklaya Street, 117198 Moscow, Russia.
Abstract
Spent coffee grounds (SCGs) are known for containing many organic compounds of interest, including carbohydrates, lipids, phenolic compounds and proteins. Therefore, we investigated them as a potential source to obtain carbon dots (CDs) via a nanotechnology approach. Herein, a comparison was performed between CDs produced by SCGs and classic precursors (e.g., citric acid and urea). The SCG-based CDs were obtained via the one-pot and solvent-free carbonization of solid samples, generating nanosized particles (2.1-3.9 nm). These nanoparticles exhibited a blue fluorescence with moderate quantum yields (2.9-5.8%) and an excitation-dependent emission characteristic of carbon dots. SCG-based CDs showed potential as environmentally relevant fluorescent probes for Fe3+ in water. More importantly, life cycle assessment studies validated the production of CDs from SCG samples as a more environmentally sustainable route, as compared to those using classic reported precursors, when considering either a weight- or a function-based functional unit.
Spent coffee grounds (SCGs) are known for containing many organic compounds of interest, including n class="Chemical">carbohydrates, lipids, phenolic compounds and proteins. Therefore, we investigated them as a potential source to obtain carbon dots (CDs) via a nanotechnology approach. Herein, a comparison was performed between CDs produced by SCGs and classic precursors (e.g., citric acid and urea). The SCG-based CDs were obtained via the one-pot and solvent-free carbonization of solid samples, generating nanosized particles (2.1-3.9 nm). These nanoparticles exhibited a blue fluorescence with moderate quantum yields (2.9-5.8%) and an excitation-dependent emission characteristic of carbon dots. SCG-based CDs showed potential as environmentally relevant fluorescent probes for Fe3+ in water. More importantly, life cycle assessment studies validated the production of CDs from SCG samples as a more environmentally sustainable route, as compared to those using classic reported precursors, when considering either a weight- or a function-based functional unit.
Authors: Inês M F Cardoso; Rita M F Cardoso; Luís Pinto da Silva; Joaquim C G Esteves da Silva Journal: Nanomaterials (Basel) Date: 2022-06-20 Impact factor: 5.719
Authors: Nuno Vale; Sara Silva; Diana Duarte; Diana M A Crista; Luís Pinto da Silva; Joaquim C G Esteves da Silva Journal: RSC Med Chem Date: 2020-12-10