Development of acolorimetric, superparamagnetic biosensor for the capture and detection of biomolecules.

Polydiacetylenes are ideal sensing materials due to their ability to change color in response to external stimuli. Here we report a new colorimetric, magnetically separable biosensor using a diacetylene monomer modified with a hydrophilic lysine derivative and superparamagnetic iron oxide nanoparticles. The particles demonstrated a distinct blue to red color transition when added to ethanol and could be quickly separated from solution with a common magnet. Surface functionalization of the particles with bovine serum albumin (BSA) showed the ability to capture and detect anti-BSA antibody from antiserum with a colorimetric response, demonstrating our biosensors can serve as a platform for diagnostic applications including point-of-care testing.