Terbium doping of graphitic carbon nitride endows a highly sensitive ratiometric fluorescence assay of alkaline phosphatase

Abstract

Terbium doped graphitic carbon nitride (g-C₃N₄:Tb) gives rise to two exceptional emissions at λ_ex/λ_em = 290/490 nm and 290/546 nm, with extremely narrow peak widths of FWHM < 12 nm as well as a large Stokes shift of >200 nm. The modification of g-C₃N₄:Tb with HOOC–PEG–COOH provides a ratiometric fluorescent probe which ensures highly sensitive detection of alkaline phosphatase (ALP) activity based on the inner filter effect (IFE).