Carbon Quantum Dot/Chitosan‐Derived Hydrogels with Photo‐stress‐pH Multiresponsiveness for Wearable Sensors. Issue 8 (21st February 2023)

• Record Type: Journal Article
• Authors: Wei, Xiaotong; Li, Jie; Hu, Zhirui; Wang, Chen; Gao, Zhiqiang; Cao, Yang; Han, Jing; Li, Yingchun
• Is Part Of: Macromolecular rapid communications. Volume 44:Issue 8(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-02-21
• Subjects: carbon quantum dots -- dual network hydrogels -- light sensing switches -- multiple responses -- smart wearable sensors; Macromolecules -- Periodicals; Polymers -- Periodicals; Chemistry -- Periodicals; 547.705
• DOI: 10.1002/marc.202200928
• Languages: English
• ISSNs: 1022-1336

Abstract

Abstract: In recent years, hydrogels have attracted extensive attention in smart sensing owing to their biocompatibility and high elasticity. However, it is still a challenge to develop hydrogels with excellent multiple responsiveness for smart wearable sensors. In this paper, a facile synthesis of carbon quantum dots (CQDs)‐doped cross‐linked chitosan quaternary/carboxymethylcellulose hydrogels (CCCDs) is presented. Designing of dual network hydrogels decorated with CQDs provides abundant crosslinking and improves the mechanical properties of the hydrogels. The hydrogel‐based strain sensor exhibits excellent sensitivity (gauge factor: 9.88), linearity ( R 2 : 0.97), stretchable ability (stress: 0.67 MPa; strain: 404%), good cyclicity, and durability. The luminescent properties are endowed by the CQDs further broaden the application of hydrogels for realizing flexible electronics. More interestingly, the strain sensor based on CCCDs hydrogel demonstrates photo responsiveness (Δ R / R 0 ≈20%) and pH responsiveness (pH range ≈4–7) performance. CCCDs hydrogels can be used for gesture recognition and light sensing switch. As a proof‐of‐concept, a smart wearable sensor is designed for monitoring human activities and detecting pH variation in human sweat during exercise. This study reveals new possibilities for further applications in wearable health monitoring. Abstract : A carbon quantum dot‐doped biomass chitosan quaternary ammonium salt‐based hydrogel is easily synthesized by immersion and thermal baking. The CQDs‐doped double network hydrogel has fluorescent properties and good stretchability. The wearable sensor based on CCCDs hydrogel has photo‐stress‐pH multiresponsiveness and can be used for gesture recognition, photosensing switch, and human activity detection.