Alkaline phosphatase activity assay with luminescent metal organic frameworks-based chemiluminescent resonance energy transfer platform

Abstract

A label–free chemiluminescent resonance energy transfer (CRET) platform was constructed for determination of alkaline phosphatase (ALP) activity. Luminescent metal organic frameworks (MOFs) were prepared by encapsulating terbium ion in frames of zinc–MOFs through hydrothermal synthesis and post–modification. The Tb@Zn–MOFs displays good luminescent property and can be capable of acting as an energy acceptor of chemiluminescence (CL) reaction between bis(2,4,6–trichlorophenyl)oxalate (TCPO) and hydrogen peroxide (H2O2), producing strong CL signal. Alkaline phosphatase (ALP) transforms its substrate adenosine 5′–monophosphate into phosphate anion via enzyme catalytic reaction. The produced phosphate anion induces a noticeable blocking effect on the CL energy transfer efficiency and results in a prominent decrease in the CL signal. The CRET platform exhibits a good linear response for ALP activity from 0.1 to 70.0 mU⋅mL−1, a low detection limit of 0.05 mU⋅mL−1 and an acceptance precision (The relative standard deviations are less than 4% for 1.0 and 10.0 mU⋅mL−1 ALP solution, n = 11). The approach was successfully applied to determination of ALP activity in human serum samples. The luminescent MOF–based CRET platform presents a feasible strategy to develop new sensors in biological fields.