Molecular fiber sensors based on surface enhanced Raman scattering (SERS).

Molecular sensors based on surface enhanced Raman scattering (SERS) and optical fibers have been widely used in biological, environmental and chemical detection procedures due to their unique advantages, such as molecular specificity, high sensitivity and flexibility. In this paper, we review the development and highlight some of the important milestones of SERS fiber sensor development with emphasis on recent work to improve the sensitivity of the fiber sensors. In particular in the area to increase the sensitivity, we've reviewed various methods of sample preparation as well as different fiber SERS sensors. One way is to strengthen the field enhancement around the surface of the probe tip and the other is to increase the number of the interacting particles during the SERS process. These techniques are known as the double substrate "sandwich" structure (DSSS) and the liquid core photonic crystal fiber (LCPCF), and in both cases the sensitivities are significantly improved. These fiber sensors were tested with Rhodamine 6G, human insulin and tryptophan and showed excellent performance.