The use of biomaterials in the synthesis of nanoparticles is one of the most up-to-date focuses in modern nanotechnologies and nanosciences. More and more research on green methods of producing metal oxide nanoparticles (NP) is taking place, with the goal to overcome the possible dangers of toxic chemicals for a safe and innocuous environment. In this study, we synthesized copper nanoparticles (CuNPs) using Fortunella margarita leaves’ extract, which reflects its novelty in the field of nanosciences. The visual observation of a color change from dark green to bluish green clearly shows the instant and spontaneous formation of CuNPs when the phytochemicals of F. margarita come in contact with Cu+2 ions. The synthesis of CuNPs was carried out at different conditions, including pH, temperature, concentration ratio and time, and were characterized with UV-Vis absorption spectra, scanning electron microscope (SEM) and X-ray diffraction (XRD). The UV-Vis analysis reveals the surface plasmon resonance property (SPR) of CuNPs, showing a characteristic absorption peak at 679 nm, while SEM reveals the spherical but agglomerated shape of CuNPs of the size within the range of 51.26–56.66 nm.

Phosphate glasses having compositions (59.5x)P2O540MgOxAgCl0.5Er2O3, where x = 0, 1.5 mol.% is prepared using melt-quenching technique. Infrared, absorption and photoluminescence spectra of Er 3+ -doped magnesium phosphate glasses have been reported. The amorphous nature of the host glass is conrmed by X-ray diraction technique. Transmission electron microscope image conrms the existence of silver nanoparticles inside the glass matrix. The localized surface plasmon resonance band of silver is found to be located around ≈ 528 nm for the Er 3+ free sample. A frequency upconversion process from infrared to visible is observed on excitation with 797 nm radiation. Furthermore, an enhancement in the emission at 540 nm and 632 nm is found due to the local eld eect of silver nanoparticles. Our ndings may contribute towards the development of solid state laser and sensors.