Noninvasive Injectable Optical Nanosensor‐Hydrogel Hybrids Detect Doxorubicin in Living Mice

Abstract While the tissue‐transparent fluorescence of single‐walled carbon nanotubes (SWCNTs) imparts substantial potential for use in non‐invasive biosensors, the development of non‐invasive systems is yet to be realized. Here, the functionality of a SWCNT‐based nanosensor in several injectable SWCNT‐hydrogel systems, ultimately finding SWCNT encapsulation in a sulfonated methylcellulose hydrogel optimal for detection of ions, small molecules, and proteins is investigated. It is found that the hydrogel system and nanosensor signal are stable for several weeks in live mice. Then, it is found that this system successfully detects local injections of the chemotherapeutic agent doxorubicin in mice. Future studies to adapt this device for the detection of other analytes in animals and, ultimately, patients are anticipated.