Optical response of magnetic fluorescent microspheres used for force spectroscopy in the evanescent field.

ABSTRACT: Force spectroscopy based on magnetic tweezers is a powerful technique for manipulating single biomolecules and studying their interactions. The resolution in magnetic probe displacement, however, needs to be commensurate with molecular sizes. To achieve the desirable sensitivity in tracking displacements of the magnetic probe, some recent approaches have combined magnetic tweezers with total internal reflection fluorescence microscopy. In this situation, a typical force probe is a polymer microsphere containing two types of optically active components: a pure absorber (magnetic nanoparticles for providing the pulling force) and a luminophore (semiconducting nanoparticles or organic dyes for fluorescent imaging). To assess the system's capability fully with regard to tracking the position o

SUBMITTER: Bijamov A 

PROVIDER: S-EPMC2912406 | biostudies-literature | 2010 Jul

REPOSITORIES: biostudies-literature