Abstract

A single-mode nonadiabatic tapered optical fiber (NATOF) sensor was utilized for studying of bimolecular interaction including DNA-DNA interaction. This work presents a simple evanescent wave sensing system based on an interferometric approach, suitable to meet the requirements of lable-free sensor systems for detecting biomolecular interactions. Furthermore basic experiments were carried out, for detecting the hybridization of 25-mer DNA with an immobilized counterpart on the surface. The wavelength shifting showed a Longmuir behavior with time and a red-shifted after the bending probe single strand DNA (ssDNA) and target ssDNA to the sensor surface. The hybridization response of complementary strands was measured at three concenteration of 200, 500, 1000 nM of ssDNA target solution. In this experiment binding constant or association constants for ssDNA-ssDNA interaction was measured to be 3.58 ×10⁵ M^-1 .

© 2011 SPIE