Hydrogel bionic skin: From bacterial antifouling and detection to efficient inactivation and self-cleaning

Timely diagnosis and treatment of bacterial infections are essential to controlling the spread of infectious diseases. However, the development of integrated antimicrobial platforms capable of in situ detection and in situ treatment remains a significant challenge. Inspired by human skin, this work developed a NIPAM/SBMA/BTB-AgNPs@MXene (NSB-AM) hydrogel bionic skin, using N-isopropylacrylamide (NIPAM) and [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA) as the hydrogel matrix, AgNPs@MXene (AM) as the filler, and bromothymol blue (BTB) as the indicator. In contrast to conventional antibacterial materials, the NSB-AM hydrogel features a multimodal antimicrobial mechanism that integrates bacterial antifouling, detection, inactivation, and self-cleaning. Experimental analysis shows that the inherent antibacterial and antifouling properties of the hydrogel can spontaneously resist bacterial contamination. When its antibacterial effect is not satisfactory, the hydrogel exhibits an optical color change that can be detected by the naked eye, enabling in situ detection of bacteria. Irradiation with near-infrared (NIR) light at this stage can achieve in situ photothermal therapy (PTT) of bacteria. Moreover, the change in the hydrophilicity and hydrophobicity of the hydrogel itself is conducive to cleaning dead bacteria and avoiding the contamination of bacterial biofilms. Furthermore, the excellent self-adhesive properties, biocompatibility, and electrical properties of the NSB-AM hydrogel enable it to adhere to the surfaces of different materials as bionic skin for real-time intelligent antibacterial applications. In summary, as an intelligent, versatile, and simple multi-functional antibacterial system, the NSB-AM hydrogel bionic skin offers novel strategies for bacterial transmission control with significant potential in healthcare and life sciences.