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Updated: Jan 18, 2026
Compact Quantum Dots for Single-molecule Imaging
Published on: October 9, 2012
Synthesis of carbon quantum dots based on hemp leaves and cysteamine for latent fingerprint detection and their
Ratchaneekorn Kampangta1, Apichart Saenchoopa1, Waranya Obrom1
1Center of Excellence for Innovation in Chemistry and Materials Chemistry Research Center, Department of Chemistry, Faculty of Science, Khon Kaen University Khon Kaen 40002 Thailand sirikul@kku.ac.th.
Abstract:
In this study, an eco-friendly one-pot hydrothermal method was used to synthesize carbon quantum dots (CQDs) using hemp leaves and cysteamine hydrochloride as the carbon and nitrogen-sulfur sources, respectively. Synthesized carbon quantum dots (HC-CQDs) were developed to achieve the clear detection of latent fingerprints (LFPs) on non-porous materials under UV-light, and their nontoxicity to humans was verified by testing on cancer cells. HC-CQDs characterized by various techniques exhibited a high quantum yield of 36.1%, and their excitation and emission peaks appeared at 354 and 434 nm, respectively. For the detection of LFPs, we prepared a fluorescence fingerprint powder utilizing HC-CQDs, cellulose nanofiber (CNF), chitosan, and cassava starch. Results showed a complete fingerprint, and it was possible to clearly identify the location and type of defects on the fingerprint (minutiae). Additionally, we performed MTT assays to understand the effect of HC-CQDs on cell viability in cancer cell lines. HC-CQDs exhibited pronounced anti-cancer activity against A549 lung carcinoma cells while demonstrating negligible cytotoxic effects on normal Vero cells. Therefore, this study successfully developed plant-based fluorescent carbon quantum dots, which can be used to prepare a fluorescent powder for detecting LFPs that is safe for forensic scientists. These HC-CQDs also possess potential in inhibiting A549 lung cancer cells, which could be further developed in the medical field.
