Exploring rolled-up Au-Ag bimetallic microtubes for surface-enhanced raman scattering sensor

A technique to design and fabricate Au-Ag bimetal microtubes for the investigation of curvature-dependent localized surface plasmon modes is demonstrated. Highly surface-enhanced Raman scattering (SERS) is observed that illustrates the distribution of localized surface plasmon modes leading to an enhanced electromagnetic field. A finite-difference time-domain method is also employed to simulate the electromagnetic field properties on the metal surface. The enhanced SERS performance of such noble bimetal microtubes could spur further interest in the integration of highly sensitive biosensors for rapid, nondestructive, and quantitative bioanalysis, particularly in microfluidics.