Bio-waste derived multifunctional carbon dots for white light generation, forensic and antibacterial applications

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Chemistry., 2024-05, Vol.450, p.115456, Article 115456
• Main Authors: Varghese, Meera, Jayaram, Saranya, Sarojini, Suma, Kumbhakar, Partha, Balachandran, Manoj
• Format: Article
• Language: English
• Subjects: Carbon dots; Green synthesis; Latent fingerprint; Solid-state fluorescence; White light-emitting diode
• ISSN: 1010-6030; 1873-2666
• DOI: 10.1016/j.jphotochem.2023.115456

[Display omitted] •Green synthesis of solid state fluorescent carbon dots has been achieved via a facile microwave method.•The obtained carbon dots were successfully utilized for the fabrication of white LED.•Fluorescent finger print imaging on various substrates was realized by using the carbon dots as dusting powder.•Antibacterial potential of the carbon dots was confirmed against gram-positive and gram-negative bacteria. The synthesis of multi-colour emitting solid-state fluorescent (SSF) carbon dots (CDs) is a challenging task due to the phenomenon of aggregation-induced self-quenching. However, this study presents an efficacious method to synthesize CDs from the sap stain of the cupressus lusitanica tree (cl-CDs) via a simple one-step microwave treatment. The resulting SSF CDs exhibited a particle size of approximately 3 nm, high stability, and remarkable efficacy in light conversion when coated on a UV light emitting diode (UV LED). The ensuing coating generated white light with CIE colour coordinates of (0.33, 0.34) and a high luminescence efficiency of approximately 671 L/W. The fluorescence capabilities exhibited by the cl-CDs in response to 254 nm and 365 nm UV light excitation make them an ideal choice for developing fluorescent inks to prevent counterfeiting. Moreover, the study investigated the notable fluorescence properties of cl-CDs as a luminescent fingerprint powder for the recognition of latent fingerprints on various surfaces. Additionally, the antibacterial potential of cl-CDs was evaluated against gram-positive and gram-negative bacteria, where the cl-CDs were utilized as an antibacterial dusting powder for fluorescent imaging of latent fingerprints on different substrates. Therefore, we believe that our present work offers a plethora of exciting possibilities for the multifunctional application of SSF green CDs with significant implications in white light generation, counterfeiting prevention, forensic applications, and healthcare.