Synthesis of fluorescent carbon nanoparticles from fruit peels by microwave method and use for fingerprint visualization

Fluorescent carbon nanoparticles, which facilitate the integration of chemistry with other scientific fields under a common umbrella, are a biomarker group known for high fluorescence activity and versatility across many applications. This key biomarker group exhibits high selectivity and often functions in biological systems. While nanoparticles are widely used in various identification studies, fingerprint imaging is a notable example. Imaging latent fingerprints, the most common type encountered at crime scenes, provides crucial evidence in investigations. Peels of four different fruits—orange, pineapple, mango, and avocado—were synthesized as nanoparticles using a green microwave-based approach, then employed for latent fingerprint imaging. These nanoparticles were characterized through ultraviolet (UV), infrared (IR), and fluorescence spectroscopy, along with Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) analysis. They were produced with sizes less than 100 nm, as defined. Fingerprints were visualized effectively for identification, with scores of at least 4 out of 5. Photographs of the fingerprints were taken from surfaces using fingerprint foil to assess their suitability for identification. The advantages of nanoparticles were highlighted through the photographs obtained and compared with current methods. Ultimately, eco-friendly and effective products were successfully developed. KEY WORDS: Chemistry, Nanoparticle, Green chemistry, Fingerprint, Forensic sciences Bull. Chem. Soc. Ethiop. 2026, 40(2), 353-367 DOI: https://dx.doi.org/10.4314/bcse.v40i2.7