Optical imaging is a popular research and diagnostic tool for performing quick, cost-effective and simple imaging of tumors and understanding disease pathology. However, current fluorescent dyes require a short wavelength excitation to induce luminescence which can only penetrate soft tissue up to 2 mm. This can results in inaccurate images, particularly during animal experiments begging the need for an emitter which requires no external input to activate its luminescence. Jung-Jae Lee and co-workers at the University of Colorado have fabricated biocompatible glycol-chitosan nanoparticles (CNPs) which do not need any input for induction of luminescence for cancer imaging. These CNPs emit near-infrared light for up to 48 hours, only when warmed to body temperature, and provide an imaging depth of more than 4 cm. The CNPs also show low toxicity and can be stored for extensively long periods at low temperatures. The large tissue penetration depth and long timescale can provide clinicians with sharper and more exact images and should have an easy implementation in the clinic.