We present a study on diopside nanotracers with persistent luminescence properties in the red-near IR range for small animal imaging. In this paper we have focused our attention on improving the persistent luminescence of diopside nanoparticles doped with transition metal and lanthanide ions. Earlier study showed that Pr3+ is the most suitable Ln3+ electron trap in Eu2+, Mn 2+ doped diopside lattice. Here, we report an optimization of both chemical composition of CaMgSi2O6 matrix and Eu, Mn, Pr doping elements to improve persistent luminescence. These new inorganic persistent luminescent nanoparticles (i-PLNPs) emit in the red-near infrared range for several hours and can master the difficulties due to the biological environment.