Fluorescence turn-on detection of protamine based on aggregation-induced emission enhancement characteristics of 4-(6'-carboxyl)hexyloxysalicylaldehyde azine.

A novel fluorescence turn-on method for sensitive and selective detection of protamine was developed based on aggregation-induced emission enhancement (AIEE) characteristics of 4-(6'-carboxyl)hexyloxysalicylaldehyde azine (CHSA) induced by electrostatic interaction between protamine and CHSA(-). Under optimal conditions described, a large Stokes shift of approximately 198 nm could be observed, and the fluorescence enhancement at 538 nm was linearly related to the concentration of protamine in the range of 0.6-18 microg mL(-1) with the relative correlation coefficient of R(2) = 0.