Geothermal silica-based fluorescent nanoparticles for the visualization of latent fingerprints

Abstract

The development of silica nanoparticles from the waste of geothermal power plants and their subsequent modification using a fluorescent dye, rhodamine 6G (R-6G), has been reported. The optimum specific surface area of the silica nanoparticles before modification was 289.2 m2 g–1. After modification, the intrinsic properties of the fluorescent silica nanoparticles were studied, and the results showed that they were in their amorphous phase, with a particle size of 5–10 nm. We proposed that the interaction between R-6G and the silica nanoparticle surface was due to the hydrogen bonding, using the results from the Fourier transform infrared spectroscopy. The obtained fluorescent silica nanoparticles had excellent fluorescence enhancement of 2-fold compared to R-6G in its original state. This study reports, for the first time, the synthesis of fluorescent nanoparticles from geothermal silica and its ability to visualize latent fingerprints on different smooth dry surfaces, making it an excellent candidate for fluorescent powders in forensic applications.