Yong Chen, Min Qiao, Zhen Yan, Molin Qin, Haonan Peng, Ruijuan Wen, Jinglin Kong, Taihong Liu*, Liping Ding*, and Yu Fang. Adv. Funct. Mater. 2026, e78542. https://doi.org/10.1002/adfm.78542

Integrating smart detection functionality into mechanically robust films is essential for developing high-performance flexible sensors, in which miniaturized and portable sensing devices play an indispensable role. Organophosphorus nerve agents among chemical warfare agents pose severe risks to public safety, and the demand for portable on-site detection devices is increasingly urgent.

In this work, a TPE-HP nanofilm was fabricated via a dynamic condensation strategy at the air-liquid interface, by integrating a hydrazide-functionalized pillar[5]arene (HP5A) with an aggregation-induced emission building block (TFPE). The nanofilm exhibits a smooth surface, a tunable thickness (457-746 nm), and favorable mechanical properties including self-standing, high puncture resistance, and cyclic fatigue resistance. The maximum puncture resistance strength reaches 0.60 kN mm^-1, and anti-fatigue performance is maintained over 50 consecutive loading-unloading cycles. The nanofilm exhibits a photoluminescence quantum yield of 29.7% and emits yellow-green fluorescence under 365 nm UV illumination. Using the nanofilm as the sensing unit, a laminated and portable sensing platform was constructed, enabling rapid, reversible, and ultra-sensitive detection of the nerve agent simulant diethyl chlorophosphate (DCP), with a limit of detection of 0.132 ppt. The response remains stable over 100 cycles, and reliability was verified by double-blind field tests. The sensing mechanism is attributed to the attack of the electrophilic phosphorus atom in DCP on the acylhydrazone structure, forming a phosphorylated intermediate, followed by protonation, accompanied by fluorescence red-shift and quenching. The nanofilm was further applied to the detection of the real nerve agent sarin, achieving practical detection limits of 1.0 mM in the solution-phase and 40.0 µg cm^-3 in the gas-phase, with visual monitoring realized via RGB analysis. This work not only combines high-performance fluorescence detection functionality into a robust nanofilm, but also achieves a field-deployable sensing prototype toward organophosphorus nerve agents.

Fig. 1. Schematic illustration of TPE-HP nanofilm fabrication and the sensing performance toward diethyl chlorophosphate (DCP) and sarin

Fig. 2. (a) Photographs of the TPE-HP nanofilms with the square and circular shapes under daylight and a 365 nm UV lamp. (b) Optical photos of the nanofilm self-standing on a rubber ring, and the nanofilm poked with a sharp object. (c) SEM image of the nanofilms on a silicon wafer. Optical photographs of the TPE-HP nanofilm in the flattening (d), crimping (e), curling (f), and twisting (g) states. (h) Stress-strain curves for nanofilms with varying thicknesses. (i) Linear relationships of both puncture resistance and puncture resistance strength as a function of nanofilm thickness. (j) Cyclic loading-unloading stress-strain scan curves and corresponding stress changes under different strains.

Fig. 3. (a-b) Fluorescence responses of the TPE-HP nanofilm to varying DCP vapor concentrations (0-132 ppm). (c) Selectivity evaluation: fluorescence response of the nanofilm to DCP (c ∼132 ppm) versus potential interferents. (d) Schematic analysis of the color and RGB changes. (e) Time-dependent fluorescence changes of the TPE-HP nanofilms under UV light upon exposure to Sarin in the solution phase. (f) Concentration-dependent fluorescence response of the nanofilm to Sarin in solution (i) and gas (ii) phase. Gray value and R/G ratio extracted from visualization photographs upon solution-phase (h) and gas-phase (i) Sarin exposure (corresponding to f-i and f-ii, respectively).

First Author: Chen Yong, doctoral candidate, Shaanxi Normal University

Correspondence Authors: Prof. Ding Liping and Prof. Liu Taihong, Shaanxi Normal University

Full Text Link: https://doi.org/10.1002/adfm.78542