Upconversion nanoparticles exhibit unique optical properties, making them attractive for applications in bioimaging, sensing, and disease management. However, their potential toxicity remains a substantial concern. This review aims to provide a in-depth analysis of the toxicity linked with upconversion nanoparticles. It investigates various aspects

Zinc oxide is a compound renowned for its remarkable ability to shield delicate skin. This gentle component has long been used in a number of skincare products, from sunscreens to diaper rash creams, due to its remarkable protective properties. Establishing a physical barrier on the skin's exterior, zinc oxide effectively reflects harmful radiati