OICC Press Trends in Phytochemical Research 2588-3631 8 2 2024 09 21 Green synthesis of carbon quantum dots and its composite with Ag/chitosan using citrus fruit extracts 141 148 10.71596/tpr.2024.1126088 EN Behnam Mahdavi Department of Chemistry, Faculty of Sciences, Hakim Sabzevari University, Sabzevar, 96179-76487, Iran Ehsan Koushki Department of Physics, Faculty of basic science, Hakim Sabzevari University, Sabzevar, Iran Behnaz Noori Dolouie Department of Chemistry, Faculty of Sciences, Hakim Sabzevari University, Sabzevar, 96179-76487, Iran Majid Mohammadhosseini Department of Chemistry and Biochemistry, College of Basic Sciences, Shahrood Branch, Islamic Azad University, Shahrood, Iran Journal Article 2024 09 21 Quantum dots are small semiconductors less than 50 nanometers in size, exhibiting unique optical and electronic properties due to quantum mechanics. Carbon quantum dots (CQDs) are particularly popular due to their size-dependent fluorescence, non-toxicity, biocompatibility, and ease of access. CQDs have significant potential applications in various chemical fields. In this study, CQDs were successfully synthesized using a green, one-step hydrothermal method involving citrus (tangerine). The synthesized CQDs were characterized using UV-VIS, XRD, IR, and TEM methods. The CQDs were then reacted with silver oxide to form CQD/Ag composite, and chitosan polymer was used to synthesize carbon quantum dots/Ag/Chitosan (CQD/Ag/Chit) bio-composite. The product was characterized using ultraviolet and infrared spectroscopy to confirm the bonds. This composite has potential applications in biological fields, as chitosan and silver have strong antibacterial properties, and their combination with active CQDs can enhance these properties.