Recent progress in stimulus-responsive hydrogel-based sensors for inflammation-associated diagnosis and surveillance

Inflammation, especially chronic inflammatory diseases, is one of the leading causes of death worldwide. Prompt diagnosis and surveillance of inflammation state can effectively identify subclinical changes and guide health management, thereby improving patients’ prognosis and enhancing their life quality. Given the limitations (e.g., labor-intensive and time-consuming processes) of conventional diagnostic techniques, various stimulus-responsive hydrogels have been developed as sensors to monitor physiological signals or biomarkers because of their remarkable biodegradability, high sensitivity, rapid testing time, and user-friendly operation. These characteristics make the stimulus-responsive hydrogel sensors highly promising for inflammation-associated diagnosis and surveillance. Herein, this review provides an updated overview of the recent progress in stimulus-responsive hydrogel sensors for inflammation diagnosis and surveillance, including: i) mechanisms of inflammation and the necessity of inflammation-related diagnosis and monitoring; ii) the classification and development of stimulus-responsive hydrogel sensors based on sensing mechanisms; and iii) the current strategies for employing stimulus-responsive hydrogel sensors to facilitate the diagnosis of inflammation and monitoring of inflammation-related indicators from infectious and aseptic inflammation. Overall, this review outlines the present status of stimulus-responsive hydrogel sensors in inflammation-related diagnosis and surveillance, offering perspectives to expedite the transformation and integration of interdisciplinary knowledge and contribute to a deeper comprehension of the ongoing advancements and future development in stimulus-responsive hydrogel sensor technology.