Interferometric methods for label-free molecular interaction studies.

Abstract

Interferometry has long been a valuable tool for measuring both the micro- and macroworlds, from solar dimensions to DNA interactions. On the biosensing frontier, a number of interferometric systems have been developed which offer significant advantages over traditional methods for measuring molecular interactions. In particular, interferometry enables the detection and study of binding events without the use of expensive and disruptive labels. Recent advancements in technologies utilizing interferometry have made significant improvements in the last several years. For example, diffraction optics has been improved through the use of nanowire gratings and multiple geometries, resulting in enhanced multiplexing and an increased instrument dynamic range. Innovations in dual polarization have demonstrated the ability to measure kinetics while simultaneously capturing structural information about the binding partners. Waveguiding microresonators, such as the microring resonator, have shown exquisite sensitivities while maintaining a straightforward and inexpensive multiplex format. New biosensing technologies have also come forward, such as backscattering interferometry which uniquely offers the additional advantage of measuring binding interactions in free solution while still using small amounts of sample.