Recent developments of low-toxicity NIR II quantum dots for sensing and bioimaging

Quantum dots (QDs) have been extensively studied for their unique optical and electronic properties such as size-dependent emissions, easy manipulation of surface properties, and high photostabilities, thereby being applicable in various fields. In particular, QDs with second near-infrared emission (NIR II QDs) are promising, especially in the biological field. With the progress in nanotechnology, recently, syntheses and applications of I-IV based NIR QDs have increased rapidly. Hence, a comprehensive summary is presented along with the future prospects.