An efficient human serum albumin-assisted fluorescence approach for hemin detection

Hemin, an iron (III) complex of protoporphyrin IX dissociated from met Hb, exhibits many biological functions. The excess of hemin can be extremely toxic, such as permeabilizing cellular membranes and oxidizing proteins, lipids and nucleic acids. Therefore, it is of great significance to achieve hemin detection. Here, a simple and environmental-friendly fluorescence-based approach for hemin detection is reported by using synthesized dicyanomethylene-4H-pyrans-morpholine (DCM-ML) as a fluorescent signal reporter molecule in the presence of human serum albumin (HSA). DCM-ML is non-fluorescent in aqueous solution, but emits 630 nm fluorescence signal with HSA. Upon hemin addition, the specific competitive-binding towards HSA results in the release of DCM-ML reporter, accompanied by a gradual decrease of fluorescence intensity of the DCM-ML/HSA system. Importantly, the fluorescence intensity at 630 nm exhibits a good linear relationship (R2 > 0.99) with the added concentration of hemin at the range of 0–2.8μmol/L, giving a quite low detection limit of 9.84 nmol/L in PBS buffer. The DCM-ML/HSA system possesses strong anti-interference capacity against other biomolecules or ions, and fast response time (30 s) for hemin and a wide pH range of 7–10 is generally suitable for the detection system. At last, the applications of DCM-ML/HSA system for hemin detection in environmental and biological systems are successfully demonstrated, indicating its practical application potential in the future.