Advances in Optical and Photonic Biosensors: Innovations, Applications, and Future Perspectives

Biomolecular detection has been revolutionized by the integration of advanced optical and photonic technologies with biosensors, offering unprecedented sensitivity and specificity. This review covers recent advances in biosensor technologies that exploit 2D materials, photonic crystals, and plasmonic enhancements for biomedical applications.

Graphene, MXenes, transition metal dichalcogenides, and 2D materials have been introduced into the field of optical biosensors, where they enhance detection by Surface Plasmon Resonance and Fluorescence Resonance Energy Transfer techniques. Similarly, with photonic crystal-based biosensors, such as one-dimensional photonic crystals (1D PCs), rapid and sensitive bacterial detection has been developed. Quantum dots and plasmonic nanomaterials connectedly form biosensors that have improved optical responses, thereby broadening their application in medical diagnostics.

Innovations in photonic biosensors have been applied in waterborne pathogen detection where multilayer photonic crystal structures break symmetry upon interaction with bacterial samples and produce unique resonance shifts. These systems, optimized based on transfer matrix methods, demonstrate enhanced sensitivity, along with superior performance compared to previously designed ones. Furthermore, SPR biosensors based on PCF that are co-modified with gold nanoparticles and polydopamine display excellent biosensing capabilities for immunoassays at low detection limits and high refractive index sensitivity.

Silicon-on-insulator (SOI)-based optofluidic biosensor arrays offer a promising multi-tumor marker detection tool for cancer diagnostics. Utilizing nanobeam resonator transducers and microfluidic integration, these biosensors offer label-free, high-sensitivity detection of carcinoembryonic antigens, thus leading to point-of-care diagnostics.

There remain several challenges with these advances: material stability, reproducibility, and translation to the clinical arena. Research should be concentrated on overcoming such barriers through sustainable material synthesis, better fabrication techniques, and more integrated biomedical systems that would finally translate to the commercialization of next-generation biosensors.