Highly fluorescent nitrogen-doped carbon dots derived from jengkol peels (Archindendron pauciflorum) by solvothermal synthesis for sensitive Hg²⁺ ions detection

• Main Authors: Prayugo, Aniza Salviana, Marpongahtun, Gea, Saharman, Daulay, Amru, Harahap, Mahyuni, Siow, Jonathan, Goei, Ronn, Tok, Alfred Iing Yoong
• Other Authors: School of Chemistry, Chemical Engineering and Biotechnology
• Format: Article
• Language: English
• Published: 2023
• Subjects: Engineering::Bioengineering; Carbon Dots; Jengkol Peels
• Online Access: https://hdl.handle.net/10356/171894
• Institution: Nanyang Technological University

A facile synthesis method involving a one-step solvothermal method is demonstrated in producing fluorescent nitrogen-doped carbon dots (N-CDs) by employing biomass waste (Jengkol peels) and ethylenediamine as a source for carbon and nitrogen. The synthesized N-CDs are spherical nanoparticles with an average size of 4.495 nm, exhibit solubility in water, emit bluish-green fluorescence and a high quantum yield of up to 42%. By using UV–Visible, FTIR, XPS, HR-TEM and Photoluminescence analysis, the as-prepared N-CDs were verified. We demonstrate that nitrogen doping increases fluorescence emission intensity to its radiative recombination of the π − π∗ transitions at C[dbnd]C and n − π∗ at C[dbnd]O or C[dbnd]N. an optimized excitation at 370 nm, the N-CDs exhibited strong PL emission at 522 nm. Under optimized conditions, N-CDs can be used to detect Hg2+ ions based on quenched fluorescence phenomenon. The result reveals excellent selectivity and sensitivity to Hg2+ ions with a detection range of 0.5 μM–4.5 μM. The resulting N-CDs may be used for detecting Hg2+ ions in cosmetics and tap water.