We synthesized Mg and Cu caged ZnO nanoparticles by considering polyvinyl alcohol (PVA), Poly vinylpyrrolidone (PVP) and biotin (BT) as organic stablizer by chemical co-precipitation route at room temperature. All the synthesized materials were characterized by X-ray diffraction (XRD), showed good crystallinity at low dimension with stabilized crystallite size. No uneanted phase formation was detected. High resolution transmission electron microscopy (HRTEM) images of crystallite planes of PVP caped Mg doped ZnO and PVA caped Cu doped ZnO suggesting that the prepared particles are mostly multi-domain crystallites. The average particles diameter in the case of PVP caped Mg doped ZnO and PVA caped Cu doped ZnO are around 50 nm and 38 nm respectively. The particle sizes are controlled by using different capping agents PVA, PVP and biotin. Photoluminescence spectroscopy (PL) shows another green wider emission band from 450 nm to 650 nm in the visible spectral range, apart from UV band, which has been frequently assigned to several intrinsic and extrinsic defects. The band gap of the doped ZnO nanoparticles was estimated from the UV-Vis absorption spectra. The energy gap estimated for all samples are found to be decreases due to the effect of the dopant, in comparison to the energy gap of bulk ZnO (3.37 eV). Raman spectra show several peaks characteristic to the defects of oxygen vacancies, Zn interstitials and vibrational modes in ZnO.