Optical imaging for biomedical applications holds much promise, particularly at near infrared I and II windows. However, the few NIR dyes are often toxic and are prone to photobleaching, while there are barely any NIR-II dyes. Semiconductor quantum dots (QDs) have tunable bandgaps into the NIR-II window, resist photobleaching, and have high quantum yields; however, QDs are traditionally made of cadmium, lead, or other toxic components. Furthermore, these QDs accumulate in vital organs and are cleared on the scale of months to years, limiting clinical relevance.
We have recently developed biodegradable, non-toxic QD platform composed of earth-abundant materials that can be cleared in under 1 month from all essential organs. Furthermore, this material exhibits a tunable bandgap out to 0.9 eV, reaching the NIR-II window. We demonstrate the degradability of this material in vitro and in vivo, as well as demonstrate its biocompatibility in a murine model.
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