This article describes the use of nanostructured probes to enhance optical and vibrational spectroscopic imaging for biomedical applications. Engineered probes and surfaces are promising tools for enhancing signals for ultrasensitive detection of diseases like carcinoma. Two methods of interest are surface-enhanced infrared absorption (SEIRA) spectroscopy and surface-enhanced Raman spectroscopy (SERS) for IR and Raman modalities, respectively. SERS and SEIRA can be broadly categorized under a common modality termed surface-enhanced vibrational spectroscopy. This article first reviews various breakthrough findings reported in SERS and SEIRA, along with different types ofsubstrates and contrast agents used in realizing the enhancement and theories proposed to explain these findings. It then considers the configurations of nano-LAMPs and presents example results demonstrating their optical resonances and tunability. Finally, it evaluates a few techniques for fabricating multilayered nanoparticles and highlights some issues with respect to fabrication.
