Tough, High stretched, Self‐healing C‐dots/Hydrophobically Associated Composited Hydrogels and Their Use for a Fluorescence Sensing Platform

Abstract In this paper, about 3.5 nm spherical carbon nanodots (C‐dots) were prepared through simple hydrothermal method, then they were introduced into the hydrophobically associated (HA) hydrogels. A new class of double physically crosslinked hydrogels (HCD hydrogels) were successfully prepared. C‐dots act as physical crosslinker in HA physically cross‐linked PAM network, and the hydrogen bond interaction between C‐dots and PAM chains endows the hydrogel with extraordinarily mechanical, high stretched and self‐healing properties. Moreover, introduction of C‐dots gives HCD hydrogels excellent fluorescence properties and good photostability. The location of emision‐wavelength of HCD hydrogel was independent of excitation‐wavelength, while the fluorescence intensity depended on excitation‐wavelength, and increased linearly with the increased concentration of C‐dots. The sensing HCD hydrogel platform based upon ROS of detecting H 2 O 2 was also explored. ROS formed by decomposition of H 2 O 2 induced fluorescence quench of hydrogels. The fluorescence intensity ratio (I 0 /I) of the H 2 O 2 ‐HCD at 550 nm correlated linearly with the concentration of H 2 O 2 in the range of 0.01‐25 μM. Impressively, this fluorescence sensor exhibited high sensitivity, simplicity, cost‐efficiency and broad applicability. Consequently our study demonstrates a general approach to prepare the robust and self‐healing hydrogels which have application potential in sensing fields.