Dal Fovo Alice, Cicchi Riccardo, Gagliardi Claudia, Baria Enrico, Fioravanti Marco, Fontana Raffaella
National Research Council-National Institute of Optics, Largo E. Fermi, 6, 50125 Florence, Italy.
European Laboratory for Non-Linear Spectroscopy (LENS), Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy.
Polymers (Basel). 2024 Dec 22;16(24):3590. doi: 10.3390/polym16243590.
Understanding the deterioration processes in wooden artefacts is essential for accurately assessing their conservation status and developing effective preservation strategies. Advanced imaging techniques are currently being explored to study the impact of chemical changes on the structural and mechanical properties of wood. Nonlinear optical modalities, including second harmonic generation (SHG) and two-photon excited fluorescence (TPEF), combined with fluorescence lifetime imaging microscopy (FLIM), offer a promising non-destructive diagnostic method for evaluating lignocellulose-based materials. In this study, we employed a nonlinear multimodal approach to examine the effects of artificially induced delignification on samples of Norway spruce () and European beech () subjected to increasing treatment durations. The integration of SHG/TPEF imaging and multi-component fluorescence lifetime analysis enabled the detection of localized variations in nonlinear signals and τ-phase of key biopolymers within wood cell walls. This methodology provides a powerful tool for early detection of wood deterioration, facilitating proactive conservation efforts of wooden artefacts.
了解木制文物的劣化过程对于准确评估其保存状况和制定有效的保护策略至关重要。目前正在探索先进的成像技术，以研究化学变化对木材结构和力学性能的影响。非线性光学模态，包括二次谐波产生（SHG）和双光子激发荧光（TPEF），与荧光寿命成像显微镜（FLIM）相结合，为评估木质纤维素基材料提供了一种很有前景的无损诊断方法。在本研究中，我们采用非线性多模态方法，研究了人工诱导脱木质素对挪威云杉（）和欧洲山毛榉（）样本在增加处理时间后的影响。SHG/TPEF成像与多组分荧光寿命分析的结合，能够检测木材细胞壁内关键生物聚合物的非线性信号和τ相的局部变化。该方法为早期检测木材劣化提供了一个强大的工具，有助于对木制文物进行积极的保护工作。
