Aqueous Gallium‐Doped Copper Indium Selenide Quantum Dots for Non‐Invasive Severity Grading of Traumatic Brain Injury

Abstract Traumatic brain injury (TBI) represents a substantial global health challenge, yet current diagnostic tools, such as CT and MRI, despite providing anatomical detail, have limitations in assessing injury severity, monitoring progression, and guiding personalized treatments. Herein, an aqueous phase‐synthesized gallium‐doped copper indium selenide quantum dot (QD) probe designed for grading TBI severity is introduced. The doping of gallium ions into the semiconductor core largely restrained the nonradiative recombination rate, thereby significantly enhancing the near‐infrared emission of the QDs. Surface modification strategies further improve QD stability and biocompatibility, ensuring high‐sensitivity imaging in vivo. In mouse models with varying TBI severities, intravenous administration of Ga‐doped QDs, combined with advanced imaging protocols and data analysis, achieved objective grading of injury severity through quantitative analysis of fluorescence signal intensity and distribution, demonstrating a remarkable correlation between QD‐derived signals and neuropathological severity. This grading result is further verified by a series of behavioral tests of the corresponding TBI mice. This QD‐based imaging strategy offers a sensitive and objective tool for TBI assessment, enabling precise grading and dynamic monitoring, thereby improving clinical decision‐making. This innovation complements existing diagnostics and has transformative potential for optimizing TBI management and patient outcomes, especially in resource‐limited settings.