| Optical fibers are a promising platform for sensor development; however, the immobilization of a probe molecule at the OF surface remains a challenge. The dynamic modification platform is a renewable, resilient, and general approach for the immobilization of probe molecules. Using this immobilization technique, a silica based OF is rendered hydrophobic through the covalent attachment of octadecyl silane. Then by immersing the hydrophobic OF in a solution of hydrophobic probe molecule, a selective sensor can be generated. The platform's resilience was demonstrated by exposing the hydrophobic OF surface to a variety of hydrolysis promoting solutions for an extended time period. Several hydrophobic fluorescein derivatives were immobilized on the surface in order to sense pH changes. pH sensing was achieved by reducing the hydrophobicity of the hydrophobic OF. Specific antibody sensing, for anti-2,4-dinitrophenol, was also demonstrated on the platform by immobilizing a hydrophobic derivative of 2,4-dinitrophenol on the hydrophobic OF surface. The sensor characteristics were described in detail. Finally, the optimal tether length for biotin derivatives to bind with avidin was determined by comparing the Kapparent of four different derivatives. |
