Photoluminescence Tuning of Rhodamine B-Dye W...

Photoluminescence Tuning of Rhodamine B-Dye With The Help of Metal Nanoparticles

Author Name : Rashidul Alam, Ajay Bharti, Binod Pokhrel

ABSTRACT Ag, Cu, and Ni nanoparticles were synthesized by chemical reduction and coupled with Rhodamine-B to investigate metal-dependent optical modulation. XRD confirmed crystalline phases, while TEM revealed spherical, well-dispersed particles with average sizes of ~50 nm (Ag), ~20 nm (Cu), and ~10 nm (Ni). UV–visible spectra showed progressive quenching of the Rhodamine B absorption band at ~550–560 nm (Ni > Cu > Ag) without peak shift, indicating dominant excited-state interactions. FTIR revealed broadening of N-related bands (1339 and 1253 cm⁻¹), confirming metal–dye coordination. Photoluminescence measurements demonstrated enhanced emission at ~560–580 nm for dye–nanoparticle composites following Ni > Ag > Cu, attributed to exciton–plasmon coupling, localized electromagnetic field enhancement, and charge transfer. These results highlight effective nanoparticle-assisted tuning of Rhodamine B photophysics and suggest potential applications in fluorescence sensing and optoelectronic devices.Top of Form