Ultrasensitive detection of biomolecules using immunoseparation and diffractometry

摘要

Systems and methods for rapid and ultrasensitive detection of target biomolecules in a sample are presented. The detection of biomolecules is achieved through a synergistic use of immunoseparation and diffractometry, and the formation of antibody-biomolecule-ligand sandwich complexes that form diffraction gratings. Characteristic diffraction patterns are then produced upon illumination of the diffraction gratings with light. The diffraction patterns can be used to detect very low amounts of biomolecules present in the sample.

主权项

1. A system for detecting biomolecules in a sample, the system comprising:
a) a substrate having a surface with rows of one dimensional diffraction grating patterns, each row separated from another row by the surface of the substrate, each row comprising a plurality of biomolecules coupled to beads b) an incident light source for delivering a beam to the substrate surface, thereby illuminating a plurality of the one-dimensional grating pattern rows, causing associated reflections from the illuminated beads and the substrate surface resulting in interference patterns generating a plurality of modes each represented by a dot in a one-dimensional pattern; c) an optical detector including a photodiode fixed on a translation stage for detecting light intensity of a first dot representing a first mode (I1) and for detecting a different second dot representing the zeroth mode (I0) and a beam expander arranged to receive reflected light from the illuminated beads and substrate surface and to separate the modes of the diffraction pattern and focus the modes on the photodiode; and d) a processor configured to compare the ratio (I1/I0) of the light intensity from the first mode and the light intensity from the second zeroth mode to a predefined calibration curve, and determine the concentration of the biomolecules.