Nanoparticles as contrast agents for in-vitro and in-vivo imaging is the most astounding, non-invasive method developed by researchers in the present scenario. To improve the multifunctionality of bio-imaging field, both Magnetic resonance imaging (MRI) and fluorescence based nanoconstructs are appreciated. In this regard, current research is dedicated to fabricate Fe3O4@NaGdF4 core–shell structure as a multifunctional, efficient probe to be useful for said purpose. Concerned core–shell is constructed in layer-by-layer approach with Fe3O4 and NaGdF4 served as core and shell respectively. Phase purity of sample is investigated through X-ray diffraction (XRD) data, seen to have inverse spinel phased Fe3O4 core and hexagonal NaGdF4. Field emission scanning electron microscopy (FESEM) images clarified the average dimension of isolated core and shell grains to be 59.86 and 62.20 nm respectively. Formation of Core-shell is verified through HRTEM images. Fourier transform infrared (FTIR) spectroscopy data reveals the functional group associated with the corresponding components. Magnetic criteria of sample are studied through room temperature magnetic field dependent magnetization (M−H) data in the range of ± 1.5 Tesla. Non-magnetic shell is seen to be dominate on magnetic core for reducing the magnetic saturation value to 9.104 emu/g from 37.891 emu/g of isolated Fe3O4 sample. Downshifting luminescence is also detected through photoluminescence (PL) study in Ultraviolet (UV) B range (309 nm) due to excitation in UVC region (271 nm) of Gd3+ energy states.