Surface-enhanced Raman scattering sensor based on D-shaped fiber

Fiber surface-enhanced Raman scattering (SERS) sensors show great potential for in vivo and in vitro detection. However, current probes based on end-polished fibers suffer from small signal due to their small active region. To overcome this, we propose and demonstrate a D-shaped fiber configuration to increase the detection area. Initial modeling has shown that most of the light can be absorbed by the SERS active layer coated on the polished fiber surface. A several orders of magnitude increase in surface area leads to substantially more detectable Raman scattered photons than those in end-tip configurations. The SERS sensor based on D-shaped fibers has been demonstrated with excellent results using rhodamine 6G. (c) 2005 American Institute of Physics.