Metal mesh devices were developed with a greater sensitivity at 10 THz than at 1 THz. Detection of a biotin-streptavidin combination was tested using these devices operating at 40 THz to evaluate their high-sensitivity capability. Experimental results showed that the combination was clearly detected label-free by a red spectral shift, indicating the possibility of using these metal mesh devices for medical inspections. (C) 2011 Published by Elsevier Ltd.