This article explores the synthesis of rare-earth-doped nanophosphors (RENPs), focusing on selecting optimal host materials like tungstates, vanadates, and aluminates to enhance luminescent properties. The incorporation of rare-earth elements, such as Eu³⁺, Tb³⁺, Dy³⁺, Sm³⁺, etc., significantly improves emission spectra and efficiency by utilizing their unique electronic configurations and interactions with the host lattice. Nanophosphors were synthesized through sol–gel, combustion, and microwave-assisted methods, resulting in materials with tunable photoluminescence, high luminous efficiency, and appropriate chromaticity for wide-bandgap lighting applications. The study further investigates upconversion nanophosphors (UCNPs), demonstrating exceptional attributes like long luminescence lifetimes, high sensitivity, low energy loss, and tunable emission spectra. These characteristics make UCNPs ideal for advanced sensing applications. Additionally, RENPs exhibit great potential in thermoluminescence dosimetry, providing accurate radiation dose measurements with minimal fading and energy-dependent responses, thus advancing both medical and environmental dosimetry.

Cancers of the oral cavity represent a major health problem, as indicated by their high incidences in many parts of the world.¹ This cancer is one of the 10 most common cancers all over the world with more than 500,000 new cases projected world wide annually.² In India, there is a high incidence of oral cancer accounting for as much as 50% of all cancers.³ It predominantly occurs among males with a male:female ratio ranging from 2 to 10 for various intraoral sites. The incidence and mortality from oral cancer have either been stable or increasing over the past three decades in several countries, with the increase being more striking particularly among young men in the western and eastern European regions.⁴ According to the Indian cancer registry,^{4, 5, 6} malignant tumors of the lip, oral cavities, and pharynx are the most commonly cited group of cancers. Between 90 and 95% of all oral cancers arise from the cells that line the mouth. Despite the easy accessibility of the oral cavity for examination, there is no satisfactory mechanism to adequately screen and detect premalignant changes and early lesions in the upper aerodigestive tract.^{7, 8} Most oral lesions are usually ignored and are not treated until they are advanced or have metastasized. At this advanced stage, the effectiveness of chemotherapy, radiotherapy, and surgery or combinations of these modalities have been disappointing. Moreover, successful therapy of oral cancer has been significantly hindered by the subsequent development of secondary tumors, which leads to treatment failure and death. Therefore, early detection of neoplastic changes in the oral cavity may be the best approach to improve results of therapy and survival rates.