Dextran-based antibacterial hydrogel-derived fluorescent sensors for the visual monitoring of AgNPs.

The unpredictable release behavior of metal nanoparticles/metal ions from metal nanoparticle-loaded hydrogels, without a suitable in situ detection method, is resulting in serious cytotoxicity. To optimize the preparation and design of antibacterial hydrogels for in situ detection of metal nanoparticles, an in-situ detection platform based on the fluorescence signal change caused by the potential surface energy transfer of silver nanoparticles (AgNPs) and carbon dots (CD) through silver mirror reaction and Schiff base reaction was established. The antimicrobial test results show that the composite antimicrobial hydrogel, with lower dosages of AgNPs and CD, exhibited a higher inhibition rate of 99.1 % against E. coli and 99.8 % against S. aureus compared to the single antimicrobial component. This suggests a potential synergistic antimicrobial activity. Furthermore, the fluorescence detection platform was established with a difference of <3 μg between detected values and actual values over a period of 72 h. This demonstrates the excellent in situ detection capability of the hydrogel in antimicrobial-related applications. [Display omitted] • The energy transfer within the hydrogels enables in-situ monitoring of the dynamic release behavior of silver nanoparticles. • Schiff base bond, hydrogen bonds, and electrostatic interactions collectively enhance the network structure of hydrogels. • Silver nanoparticles were prepared through the silver mirror reaction without the use of chemical reductants or surfactants. [ABSTRACT FROM AUTHOR]