Wu Guojie, Guan Yuchen, Li Xubin, Gong Zhenfeng, Peng Wei, Mei Liang
School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, Liaoning 116024, China.
School of Dalian University of Technology and Belarusian State University Joint Institute, Dalian University of Technology, Dalian, Liaoning 116024, China.
Anal Chem. 2025 Jul 22;97(28):15510-15515. doi: 10.1021/acs.analchem.5c03433. Epub 2025 Jul 14.
To address the challenges of low sensitivity and poor stability in conventional single-fiber photoacoustic spectroscopy, here, we present for the first time a polyethylene terephthalate (PET)-cantilever-enhanced fiber-optic photoacoustic spectroscopy (PET-CEFOPAS) system featuring an integrated PET cantilever and a dual-cavity structure that enables highly sensitive and rapid detection of trace CH. COMSOL Multiphysics finite element simulations reveal that the PET cantilever, benefiting from its low Young's modulus and flexible mechanical properties, exhibits an acoustic pressure sensitivity of 7334 nm/Pa. The theoretical resonance frequency (2638 Hz) closely matches the experimental result (2465 Hz), validating the reliability of the simulations. Experimental results further confirm that the PET cantilever combines high optical transmittance (>90% at 1550 and 1653.7 nm) with low reflectivity (<0.1). By optimizing the F-P cavity length (0.5 mm) and the photoacoustic cavity length (3.5 mm), the sensor achieves a synergistic enhancement of optical path length and sensitivity within an ultracompact volume of 10 μL. Allan deviation analysis shows that the PET-CEFOPAS system has excellent stability. The dual-cavity design reduces the CH detection limit to 440 ppb (integration time of 132 s) and shortens the gas response time to 4.5 s, resolving the long-standing trade-off between sensitivity and response speed in miniaturized PAS systems. This work offers a new solution in fiber-optic PAS for high-sensitivity, rapid gas sensing.
为应对传统单光纤光声光谱法灵敏度低和稳定性差的挑战，在此，我们首次展示了一种聚对苯二甲酸乙二酯（PET）悬臂增强光纤光声光谱（PET-CEFOPAS）系统，该系统具有集成的PET悬臂和双腔结构，能够高灵敏度且快速地检测痕量CH。COMSOL Multiphysics有限元模拟表明，PET悬臂因其低杨氏模量和灵活的机械性能，表现出7334 nm/Pa的声压灵敏度。理论共振频率（2638 Hz）与实验结果（2465 Hz）紧密匹配，验证了模拟的可靠性。实验结果进一步证实，PET悬臂兼具高透光率（在1550和1653.7 nm处>90%）和低反射率（<0.1）。通过优化法布里-珀罗（F-P）腔长度（0.5 mm）和光声腔长度（3.5 mm），该传感器在10 μL的超紧凑体积内实现了光程长度和灵敏度的协同增强。阿伦偏差分析表明，PET-CEFOPAS系统具有出色的稳定性。双腔设计将CH检测限降低至440 ppb（积分时间为132 s），并将气体响应时间缩短至4.5 s，解决了小型化光声光谱系统中长期存在的灵敏度与响应速度之间的权衡问题。这项工作为光纤光声光谱中的高灵敏度、快速气体传感提供了一种新的解决方案。
