Wang, X. W.; Cooper, K. L.; Wang, Anbo; Xu, J. C.; Wang, Z. A.; Zhang, Y.; Tu, Zhijian Jake (AIP Publishing, 2006-10-01)
The authors present a label-free method for direct detection of deoxyribonucleic acid (DNA) sequences. The capture DNA is immobilized onto the surface of a silica optical fiber tip by means of the layer-by-layer electrostatic self-assembly technique. Hybridization of target DNA with complementary capture DNA increases the optical thickness of the fiber tip. This phenomenon can be detected by demodulation of the spectrum of a Fabry-Perot cavity fabricated in the optical fiber. Experimental results demonstrate sequence specificity and sensitivity to nanogram quantities of target DNA sequences with short (similar to 5 min) hybridization time. (c) 2006 American Institute of Physics.