A Peptide-Based Electrochemical Biosensor for Facile Measurement of Whole-Blood Heparin

Graphical Peptide–heparin composites : A simple electrochemical approach for the determination of heparin level in human whole-blood is developed based on specific peptide recognition (see picture). The first peptide-based electrochemical biosensor for the measurement of the anti-coagulant heparin using electrochemical impedance spectroscopy is reported. The peptide immobilized on the electrode interface specially captures heparin with high affinity. The composites formed on the electrode can thus effectively repel electrochemical species, leading to an increase in interfacial charge transfer resistance. After analyzing the electrochemical signals, a linear detection range from 0.05 to 10.0 μg/mL is obtained. The detection limit is calculated to be 0.01 μg/mL, which is extremely low with such a simple sensing mechanism. Moreover, the proposed method has potential application for sensitive and separation-free detection of heparin in whole-blood samples.