Kuoxi Xu

The significance of hypochlorous acid in beverages, foodstuffs, as well as in pathological and physiological processes, has spurred substantial research efforts toward its real-time, in-field detection. In this work, phenothiazine and cyanoethylpyridine were joined through a vinyl bridge to construct a new ratiometric fluorescent probe, PVC. The probe features high specificity and sensitivity (LOD = 1.20 μM), alongside a rapid response time (≤110 s), a remarkably large Stokes shift (265 nm), and satisfactory photostability. Notably, the detection mechanism for HClO via a cascade process, oxidation sulfur formation sulfoxide, oxidation N, N-dimethylthiocarbamoyl group following intramolecular cyclization to formation of a pyran-imine. The probe PVC was successfully employed for HClO detection in both water and food matrices. Moreover, its ability to visualize endogenous and exogenous HClO in living cells and mice renders PVC a versatile platform for exploring a broad spectrum of HClO-associated physiological and pathological processes.

Biomimetic spider silk achieves remarkable functionalities through hierarchical architectures with highly oriented crystalline domains, offering potential across multiple disciplines. However, achieving uniform alignment and spatial control of nanocrystalline domains remains a critical challenge, limiting the realization of structure-derived optical and mechanical functionalities in bioinspired systems. Here, we develop an ultrastrong, transparent photonic hydrogel composed of cellulose nanocrystals (CNCs), wherein a programmable five-stage stretching-pause process enables precise alignment of CNC domains without sacrificing their intrinsic chirality—unattainable in conventional flexible polymers. This strategy facilitates uniform nanocrystal reorientation (orientation factor = 0.91) and transforms the porous network into aligned nanofibril bundles, yielding optical transparency (>90%) with anisotropic polarization responses, superior mechanical strength (61.6 MPa), toughness (251.8 MJ·m ⁻³ ), and fatigue resistance (226.7 kJ·m ⁻² ). The flexible hydrogel resists creasing and serves as a sustainable scattering polarizer for programmable polarized displays and secure information encryption, providing a versatile platform for advanced optical and electronic applications.

A novel fluorescent probe, 2-(2-aminothiazol-4-yl)-6-(benzo[d]thiazol-2-yl)-4-methylphenol (HBTT), was designed and synthesized for the sequential detection of Cu²⁺ ions. The introduction of an aminothiazole moiety extended the conjugation system and supplied additional coordination sites, thereby conferring upon HBTT optimal photophysical properties and strong metal ion affinity. In the presence of Cu²⁺, the strong fluorescence of HBTT was efficiently quenched due to the formation of a 1:1 HBTT–Cu²⁺ complex. The addition of P₂O₇⁴⁻ restored the fluorescence because of the competitive binding of Cu²⁺ by P₂O₇⁴⁻, demonstrating a reversible response. The probe exhibited high selectivity, larger Stoke’s shift, fast response, and low detection limits for Cu²⁺ ion. The application of probe HBTT for the fluorescence analysis of Cu²⁺ in actual water samples was investigated, confirming that the probe possesses significant potential for direct on-site environmental detection. Furthermore, HBTT showed low cytotoxicity and was successfully applied for sequential imaging of Cu²⁺ in SHSY5Y cells using confocal microscopy, highlighting its potential for monitoring these species in biological systems.

A novel fluorescent probe, HBTT, was designed and synthesized for the sequential detection of Cu²⁺ and pyrophosphate (P₂O₇⁴⁻). The introduction of an aminothiazole moiety extended the conjugation system and supplied additional coordination sites, thereby conferring upon HBTT optimal photophysical properties and strong metal ion affinity. In the presence of Cu²⁺, the strong fluorescence of HBTT was efficiently quenched due to the formation of a 1:1 HBTT–Cu²⁺ complex. Subsequent addition of P₂O₇⁴⁻ restored the fluorescence because of the competitive binding of Cu²⁺ by P₂O₇⁴⁻, demonstrating a reversible ”on-off-on” response. The probe exhibited high selectivity, larger Stokes shift, fast response, and low detection limits for both analytes. The application of probe HBTT for the fluorescence analysis of Cu²⁺ and P₂O₇⁴⁻ in actual water samples was investigated, confirming that the probe possesses significant potential for direct on-site environmental detection of the two ions. Furthermore, HBTT showed low cytotoxicity and was successfully applied for sequential imaging of Cu²⁺ and P₂O₇⁴⁻ in SHSY5Y cells using confocal microscopy, highlighting its potential for monitoring these species in biological systems.

Herein, an ethylene-bridge bond of diethylaminocoumarin and dicyanoisophorone unit fluorescence probe was developed for the specific detection of HClO. The sensing mechanism involves HClO-induced cleavage of the N,N-dimethylthiocarbamate group, oxidation-triggered ethylene bridge rearrangement, ultimately leading to the formation of a unique thiophene ring structure. The probe was successfully applied for simultaneous detection of HClO in beverage and food samples. Moreover, the probe facilitated high-contrast imaging of both endogenous and exogenous HClO in live cells and in vivo mouse models, offering a powerful tool for elucidating HClO-associated physiological and pathological mechanisms.