Development of a colorimetric, 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.

► We synthesized core–shell superparamagnetic nanoparticles for biosensing application.
► Functionalized nanoparticle surface with polydiacetylenes.
► Enabled rapid detection of biomarkers in complexmedia.