Micro-gas optical-fiber detection based on metal–organic framework films by photocurable deposition

Effective detection of dissolved acetylene is critical for diagnosing early faults in oil-immersed power transformers; however, achieving a synergy between high sensitivity and mechanical robustness presents a significant challenge in sensor design. We developed a photocurable composite film comprising copper-based benzene-1,3,5-tricarboxylate (HKUST-1) and butyl methacrylate (BMA) via ultraviolet crosslinking. HKUST-1 possesses a three-dimensional interconnected pore structure with uniform-sized nanocage windows (0.69-1.08 nm). The high density of Cu2+ sites enables rapid acetylene capture, achieving a rapid response time of 15 s. Coating the fiber tip with HKUST-1 creates a Fabry-Pérot interferometer (FPI) structure. Experimental gas adsorption tests and optical simulations validated the sensing probe's efficacy, demonstrating a sensitivity of 0.531 pm/ppm, a resolution of 0.716 ppm, and a detection limit of 2.11 ppm. The integration of MOFs' nanoscale confinement effects with photopolymerization presents a promising strategy for nano-engineered gas sensing.