Reversible binding and quantification of heparin and chondroitin sulfate in water using redox-stable biferrocenylene SAMs

A biferrocenylene (BFD) thiol conjugate was prepared and self-assembled on a gold surface. The resulting SAMs with their extraordinary stability in the monocationic state were used to detect and quantify heparin (3-300 × 10(-5) g L(-1) = 0.003-0.3 U mL(-1)) and chondroitin sulfate (3-250 × 10(-5) g L(-1)) in aqueous buffer by cyclic voltammetry, square wave voltammetry and surface plasmon resonance. As a proof of concept, heparin quantification was performed in a blood plasma sample. Moreover, controlled binding and release of heparin was realised by switching the BFD-SAM between the monocationic and neutral state.