An optical tweezers-based immunosensor for detection of femtomoles-per-liter concentrations of antigens |
| |
Authors: | Kristian Helmerson Rani Kishore William D Phillips Howard H Weetall |
| |
Institution: | (1) Atomic Physics Division, National Institute of Standards and Technology, 20899 Gaithersburg, MD;(2) Biotechnology Division, National Institute of Standards and Technology, 20899 Gaithersburg, MD |
| |
Abstract: | We used optical tweezers—optical trapping with focused laser beams—to pull microspheres coated with antigens off of an antibody-coated
surface. Using this technique, we could quantify the force required to separate antigen to antibody bonds. At very low surface
density of antigen, we were able to detect the single antigen to antibody binding. The force required to break the antigen-antibody
bonds and pull the microsphere off the surface was shown to increase monotonically with increasing surface density of antigens.
Using the force determination as a transducer, we were able to detect concentrations of free antigens in solution as small
as 10−15 mol/L in a competitive binding assay. |
| |
Keywords: | Optical tweezers laser trap immunosensor assay antigen antibody BSA |
本文献已被 SpringerLink 等数据库收录! |