A Novel Ion Species- and Ion Concentration-Dependent Anti-Counterfeiting Based on Ratiometric Fluorescence Sensing of CDs@MOF-Nanofibrous Films.

Traditional fluorescent anti-counterfeiting labels based on "on-off" fluorescence can be easily cloned. It is important to explore advanced anti-counterfeiting fluorescent labels with high-level security. Here, a pioneering ion species- and ion concentration-dependent anti-counterfeiting technique is developed. By successive loading Cu2+ -sensitive yellow emitted carbon dots (Y-CDs) and Cu2+ non-sensitive blue emitted carbon dots (B-CDs) into metal-organic frameworks (MOFs) and followed by electrospinning, the B&Y-CDs@MOF-nanofibrous films are prepared. The results show that the use of MOF not only avoids the fluorescence quenching of CDs but also improves the fluorescence stability. The fluorescence Cu2+ -sensitivity of the CDs@MOF-nanofibrous films can be regulated by polymer coating or lamination. The fluorescent label consisting of different Cu2+ -sensitivity films will show Cu2+ concentration-dependent decryption information. Only at a specific ion species and concentration (Cu2+ solution of 40-90 µm), the true information can be read out. Less or more concentration (<40 or >90 µm) will lead to false information. The identification of the real information depends on both the species and the concentration. After Cu2+ treatment, the fluorescence of the label can be recovered by ethylenediaminetetraacetic acid disodium (EDTA-2Na) for further recycling. This work will open up a new door for designing high-level fluorescent anti-counterfeiting labels.

Fluorescent Fiber-Shaped Aqueous Zinc-Ion Batteries for Bifunctional Multicolor-Emission/Energy-Storage Textiles.

Wearable smart textiles are natural carriers to enable imperceptible and highly permeable sensing and response to environmental conditions via the system integration of multiple functional fibers. However, the existing massive interfaces between different functional fibers significantly increase the complexity and reduce the wearability of the textile system. Thus, it is significant yet challenging to achieve all-in-one multifunctional fibers for realizing miniaturized and lightweight smart textiles with high reliability. Herein, as bifunctional electrolyte additives, fluorescent carbon dots with abundant zincophilic functional groups are introduced into electrolytes to develop fluorescent fiber-shaped aqueous zinc-ion batteries (FFAZIBs). Originating from effective dendrite suppression of Zn anodes and multiple active sites of freestanding Prussian blue cathodes, high energy density (0.17 Wh·cm-3) and long-term cyclability (78.9% capacity retention after 1500 cycles) are achieved for FFAZIBs. More importantly, the one-dimensional structure ensures the same luminance in all directions of FFAZIBs, enabling the form of multicolor display-in-battery textiles.