Viscosity & SO2-sensitive dual colorimetric effect fluorescent sensor enabled imaging detection within plant onion and biological system.

The biological microenvironment includes important parameters such as viscosity, polarity, temperature, oxygen content and pH. In particular, abnormal cell viscosity is associated with the development of major diseases. Sulphur dioxide (SO2) serves not only as an essential atmospheric pollutant but also an influential signalling molecule in biological cells, predisposing individuals to increased respiratory disease. In this work, we designed and synthesized a novel fluorescent probe CouCN-V&S with dual response to micro environmental viscosity and SO2. The probe monitored viscosity and SO2 separately through dual emission channels with a difference of 135 nm. The probe responded sensitively to SO2 (<1s) and exhibited satisfactory immunity to interference and pH stability. The probe was successfully applied to imaging cellular, intra-zebrafish viscosity and SO2 changes. Interestingly, we took onion epidermal cells as model and explored the capability of probe CouCN-V&S to image SO2 in plant cells for the first time.

Transparent cellulose-based bio-hybrid films with enhanced anti-ultraviolet, antioxidant and antibacterial performance.

Developing the biodegradable and eco-friendly materials to substitute for the traditional petroleum-derived plastics is significant, and cellulose is the most promising candidate to replace petroleum-derived plastics. However, the high-cost dissolving pulps are still the major raw materials in industry. Moreover, the traditional cellulose materials lack functions, limiting their application and service life. Herein, multi-functional cellulose/tea polyphenols (TPs) bio-hybrid films were fabricated successfully via employing low-cost waste cotton textiles as cellulose source. It was found that the cellulose/TPs films displayed high anti-ultraviolet capacity and irradiation stability without sacrificing their transparency, and UV-A and UV-B blocking values can reach 85.08 % and 99.97 %. Besides, cellulose/TPs films show up to 63 % of radical scavenging activity and possess obvious antibacterial capacity, due to the copious phenolic hydroxyls within TPs. Hence, the cellulose/TPs bio-hybrid films with enhanced anti-ultraviolet, antioxidant and antibacterial performance were manufactured successfully, which demonstrated great potentials in packaging fields.