Optical fibers are gaining increasing attention in biomedical applications due to their unique advantages, including flexibility, biocompatibility, immunity to electromagnetic interference, potential for miniaturization, and the ability to perform remote, real-time, and in situ sensing. Label-free optical fiber biosensors represent a promising alternative to conventional cancer diagnostics, offering comparable sensitivity and specificity while enabling real-time detection at ultra-low concentrations without the need for complex labeling procedures. However, the sensing performance of biosensors is fundamentally governed by surface modification. The choice of optimal functionalization strategy is dictated by the sensor type, target biomarker, and detection environment. This review paper presents a comprehensive and expanded overview of various surface functionalization methods specifically designed for cancer biomarker detection using optical fiber biosensors, including silanization, self-assembled monolayers, polymer-based coatings, and different dimensional nanomaterials (0D, 1D, and 2D). Furthermore, the emerging integration of computational methods and machine learning in optimizing functionalized optical sensing has been discussed. To the best of our knowledge, this is the first work that consolidates existing surface modification approaches into a single, cohesive resource, providing valuable insights for researchers developing next-generation fiber optic biosensors for cancer diagnostics. Moreover, the paper points out the current technical challenges and outlines the future perspectives of optical fiber-based biosensors.

β-Ga2O3 is a promising material for power electronics due to its wide bandgap and high breakdown field, but its low thermal conductivity poses challenges for heat dissipation. To address this, we employed ion beam exfoliation to fabricate β-Ga2O3 nanomembranes integrated with highly thermally conductive Si substrates. To do this, chromium ion implantation was used to induce stress and strain, forming rolled-up microtubes on (100)-oriented β-Ga2O3 single crystals. After successfully transferring these tubes onto Si substrates and performing thermal annealing, these microtubes were unrolled into nanomembranes. X-ray diffraction and Raman measurements revealed the high quality of the samples. Time-domain thermoreflectance was used to study thermal transport in these structures, confirming uniform thermal conductivity across three fabricated samples. A Debye-based thermal transport model was implemented to validate experimental results and define the main phonon scattering mechanisms. Non-equilibrium molecular dynamics simulations revealed that a thin amorphous SiO2 interlayer significantly enhanced the thermal boundary conductance (TBC) across the β-Ga2O3/Si interface by bridging the vibrational mismatch between β-Ga2O3 and Si. However, further increasing the interlayer thickness led to phonon scattering and reduced TBC, emphasizing the importance of precise interface thickness control. This study highlights ion beam exfoliation as a scalable approach for integrating β-Ga2O3 with thermally conductive substrates, providing a pathway to improved thermal management in β-Ga2O3-based power electronics.

Breast cancer remains a major cause of cancer-related mortality in women, and its substantial molecular heterogeneity highlights the need for methods capable of characterizing tumor cells at the cellular level. CD44, a transmembrane glycoprotein associated with breast cancer progression, metastasis, and cancer stem-like phenotypes, is a promising biomarker for selective recognition of aggressive, basal-like cell populations. However, conventional approaches to evaluating CD44 expression including immunohistochemistry, immunofluorescence, and flow cytometry require labeling and multi-step sample preparation. In this work, a gold-coated, polydimethylsiloxane (PDMS)-based extrinsic semi-distributed interferometric (SDI) optical fiber biosensor functionalized with anti-CD44 antibodies was developed for label-free, selective detection of CD44-expressing HCC1806 breast cancer cells. The functionalized sensor exhibited a concentration-dependent response with a limit of detection (LoD) of 2.51 cells/mL, while the antibody-free control sensor exposed to HCC1806 cells and the anti-CD44-functionalized sensor exposed to CD44-low HEK293 cells showed only minimal responses, supporting selective detection under the tested conditions. These results support the potential of the antibody-functionalized ESDI platform for label-free detection of CD44-expressing cells, providing a groundwork for its validation in clinical samples as a step toward tumor-cell diagnostics.

Understanding how irradiation-induced defects affect heat transport is essential for designing advanced ceramics for extreme environments. In this study, we investigate the impact of 710 MeV Bi swift heavy ion irradiation on the thermal conductivity of polycrystalline Si3N4 and AlN ceramics. Time-domain thermoreflectance measurements reveal a pronounced reduction in cross-plane thermal conductivity in both materials, but with distinct damage mechanisms. In Si3N4, irradiation generates amorphous latent ion tracks that progressively overlap at high fluences, leading to strong phonon scattering and a conductivity drop to near the amorphous limit (∼1 Wm−1K−1). AlN retains its crystalline framework even at high fluence, showing no evident latent track formation and only a modest reduction in heat conduction. Structural analysis such as X-ray diffraction, Raman spectroscopy, and high-resolution TEM supports these observations, indicating nanotrack-induced amorphization in Si3N4 and point defect-dominated damage in AlN. A semi-analytical Klemens–Callaway model reproduces the experimental trends, attributing scattering from cylindrical tracks in Si3N4 and scattering from point defects in AlN. Furthermore, increased Al content in Si3N4 promotes larger track radius and accelerates thermal degradation, highlighting the role of dopant chemistry in radiation tolerance. The present results provide insight into radiation-induced heat transport degradation and establish a framework for tailoring nitride ceramics towards improved radiation tolerance and controlled thermal performance in extreme environments.