Multifunctional fluorescent film sensor with H2O2 and Cu2+ dual-response for information security and food safety applications

Multifunctional film design combines AIE-H 2 O 2 probe and silica-Cu 2+ sensor. • Dual ratio sensing enables visual detection of H 2 O 2 vapor and Cu 2+ simultaneously. • Flexible film realizes encryption/decryption for anti-counterfeiting smart labels. • Film exhibits mild antimicrobial effect and food preservation function. • Integrated sensing & antibacterial features in intelligent packaging. Fluorescent sensing films are considered as powerful tools for portable detection of various analytes due to their advantages of being non-invasive, real-time and easily integrable. The multifunctional design of fluorescent film sensors plays a crucial role in expanding their practical applications in complex detection scenarios. Here, a flexible ratiometric fluorescent sensing film (PAN@SD-S@CS-TB) with mild antibacterial performance was designed for dual sensing of hydrogen peroxide (H 2 O 2 ) and Copper (II) (Cu 2+ ). Specifically, a silica nanosphere-based Cu 2+ probe was incorporated into the film fiber through co-electrospinning, and subsequently, the fiber surface was functionalized with aggregation-induced emission (AIE)-featured H 2 O 2 sensing molecules. Based on different fluorescence responses, the blue-emission of the film could be quenched upon interaction with H 2 O 2 vapor, whereas the red-emission exhibited “turn-off” behavior in the presence of Cu 2+ . This multifunctional fluorescence film was convenient for the sensitive, selective and visual detection of H 2 O 2 and Cu 2+ , with the detection limits of 27.6 ppb and 80.3 μM, respectively. Based on the multiple-responsive performance of the film, an intelligent anticounterfeiting label was constructed for information encryption and decryption. Moreover, PAN@SD-S@CS-TB demonstrated real-time detection capability in food products. Meanwhile, it exhibited certain antimicrobial properties on food surfaces, which could extend the shelf life and maintained the food freshness. The film with integrated functions of sensing and antibacterial revealed huge advantages in intelligent packaging. This study provided a novel avenue for the development of multifunctional film systems and offered great application values across various fields. Download: Download high-res image (220KB) Download: Download full-size image