Determination of fructose 1,6-bisphosphate using a double-receptor sandwich type fluorescence sensing method based on uranyl–salophen complexes Original Research Article

In this paper, we report a double-receptor sandwich type fluorescence sensing method for the determination of fructose bisphosphates (FBPs) using fructose 1,6-bisphosphate (F-1,6-BP) as a model analyte based on uranyl–salophen complexes. The solid phase receptor is an immobilized uranyl–salophen (IUS) complex which is bound on the surface of glass slides by covalent bonds. The labeled receptor is another uranyl–salophen complex containing a fluorescence group, or uranyl–salophen–fluorescein (USF). In the procedure of determining F-1,6-BP in sample solution, F-1,6-BP is first adsorbed on the surface of the glass slide through the coordination reaction of F-1,6-BP with IUS. It then binds USF through another coordination reaction to form a sandwich-type structure of IUS-F-1,6-BP-USF. The amount of F-1,6-BP is detected by the determination of the fluorescence intensity of IUS-F-1,6-BP-USF bound on the glass slide. Under optimal conditions, the linear range for the detection of F-1,6-BP is 0.05–5.0 nmol mL−1 with a detection limit of 0.027 nmol mL−1. The proposed method has been successfully applied for the determination of F-1,6-BP in real samples with satisfactory results.