Accurate identification of tissue types in surgical margins is essential for ensuring the complete removal of cancerous cells and minimizing the risk of recurrence. The objective of this study was to explore the clinical utility of Raman spectroscopy for the detection of oral squamous cell carcinoma (OSCC) in both tumor and healthy tissues obtained from surgical resection specimens during surgery. This study enrolled a total of 64 patients diagnosed with OSCC. Among the participants, approximately 50% of the cases were classified as the most advanced stage, referred to as T4. Raman experiments were conducted on cryopreserved tissue samples collected from patients diagnosed with OSCC. Prominent spectral regions containing key oral biomarkers were analyzed using the partial least squares–support vector machine (PLS–SVM) method, which is a powerful multivariate analysis technique for discriminant analysis. This approach effectively differentiated OSCC tissue from non-OSCC tissue, achieving a sensitivity of 95.7% and a specificity of 93.3% with 94.7% accuracy. In the current study, Raman analysis of fresh tissue samples showed that OSCC tissues contained significantly higher levels of nucleic acids, proteins, and several amino acids compared to the adjacent healthy tissues. In addition to differentiating between OSCC and non-OSCC tissues, we have also explored the potential of Raman spectroscopy in classifying different stages of OSCC. Specifically, we have investigated the classification of T1, T2, T3, and T4 stages based on their Raman spectra. These findings emphasize the importance of considering both stage and subsite factors in the application of Raman spectroscopy for OSCC analysis. Future work will focus on expanding our tissue sample collection to better comprehend how different subsites influence the Raman spectra of OSCC at various stages, aiming to improve diagnostic accuracy and aid in identifying tumor-free margins during surgical interventions.

Surface morphologies, light harvesting abilities, crystal structures, and excitonic properties of the formamiminium lead triiodide (FAPbI₃) based alloy perovskite thin films were investigated by using the scanning electron microscopic images, absorbance spectra, X-ray diffraction patterns, photoluminescence (PL) spectra and time-resolved PL decaying curves. Our experimental results show that the fresh Cs_xFA_1−xPbI₃, Rb_xFA_1−xPbI₃, and FAPb(SCN_xI_1−x)₃ alloy thin films are a pure α-phase perovskite crystal, a α-phase: δ-phase mixed perovskite crystal, and a PbI₂ crystal/α-phase: δ-phase mixed perovskite crystal at room temperatures, respectively. Among the three FAPbI₃ based alloy perovskite solar cells, the Cs_xFA_1−xPbI₃ solar cells have the better photovoltaic responses. It is noted that the high photocurrent density is mainly due to the formation of cube-like surface morphology and the long carrier lifetime of 368 ns when the Cs_xFA_1−xPbI₃ alloy perovskite thin film is used as the light-absorbing layer. Our findings provide the relation between the properties of the FAPbI₃ based alloy perovskite thin films and the photovoltaic responses of the resultant solar cells.