Di Turo Francesca, Moscardini Aldo, Pingue Pasqualantonio, Cardarelli Francesco
NEST Laboratory - Scuola Normale Superiore, Piazza San Silvestro 12, Pisa, Italy.
Sci Rep. 2025 Aug 27;15(1):31624. doi: 10.1038/s41598-025-16733-8.
Paper ageing is a complex and irreversible process that critically affects materials ranging from packaging to cultural heritage artefacts. While both invasive and non-invasive analytical techniques exist to assess the deterioration of paper, many approaches still present limitations in terms of sensitivity, spatial resolution, or applicability to historical artefacts. Here, we present a fully optical, non-invasive method to monitor oxidation in paper using label-free Fluorescence Lifetime Imaging Microscopy (FLIM). We show that the intrinsic fluorescence lifetime of paper changes with oxidation and that these shifts correlate strongly with FTIR indicators of ageing. Validation was performed on both modern and historical samples subjected to controlled oxidation. This approach represents the first step toward a new diagnostic methodology for monitoring the degradation of paper-based materials in sensitive contexts such as heritage science.
纸张老化是一个复杂且不可逆的过程，它对从包装材料到文化遗产文物等各类材料都有着至关重要的影响。虽然存在侵入性和非侵入性分析技术来评估纸张的老化程度，但许多方法在灵敏度、空间分辨率或对历史文物的适用性方面仍存在局限性。在此，我们提出一种全光学、非侵入性的方法，即使用无标记荧光寿命成像显微镜（FLIM）来监测纸张中的氧化过程。我们发现纸张的固有荧光寿命会随着氧化而变化，并且这些变化与老化的傅里叶变换红外光谱（FTIR）指标密切相关。我们对经过可控氧化的现代和历史样本都进行了验证。这种方法是迈向一种新诊断方法的第一步，该方法用于在遗产科学等敏感背景下监测纸质材料的降解情况。
