A Turn‐On Sensor for Highly Sensitive and Selective Detect Heparin in Human Serum Albumin

Abstract

A novel positively charged sensor, NAP‐MBT+, was designed and constructed by introducing a 2‐methylbenzothiazole cation (MBT+) into naphthalimide derivative (NAP‐phCHO) via a double carbon bond. NAP‐MBT+ can realize the detection sensitively and selectively for heparin (Hep) by “turn‐on” fluorescence emission in several seconds. NAP‐MBT+ displayed the very significant fluorescence emission enhancement only to Hep among various interference from counter ions and biomolecules. The fluorescence emission of NAP‐MBT+ to Hep depended on the electrostatic attraction between the positive and negative charges. NAP‐MBT+‐Hep assembly can be dissociated by protamine (PRTM) appearing an “off‐on‐off” signal because of the stronger affinity of Hep to PRTM. NAP‐MBT+ was successfully applied to detect Hep in 0.2 % human serum.