A turn-on chemiluminescent assay for alkaline phosphatase using two-dimensional Fe-centered metal-organic frameworks as the signaling probe

Abstract

Alkaline phosphatase (ALP) is an essential enzyme involved in cell phosphorus metabolism. Developing sensitive and accurate ALP quantitative assays is significant. In this study, a turn-on chemiluminescence (CL) analysis platform for the detection of ALP activity in human serum was established based on two-dimensional (2D) Fe-centered metal-organic frameworks with 1,3,5-benzene tricarboxylic acid as ligands (denoted as 2D Fe-BTC). The 2D Fe-BTC as the signaling probe reacts with ascorbic acid forming reduced Fe-BTC which catalyzes the luminol CL reaction producing a strong CL signal. The 2D Fe-BTC-based luminol CL reaction exhibited good CL responses when the concentration of ascorbic acid was in the range of 5-500 nM. By employing magnesium ascorbyl phosphate (MAP) as the substrate which can be hydrolyzed by ALP to generate ascorbic acid, a turn-on CL assay for the detection of ALP was established. Under optimal conditions, as low as 0.00046 U L^-1 of ALP could be sensitively detected with a linear range of 0.001-0.1 U L^-1. ALP in human serum can be detected after a simple dilution process without any other pretreatment.

Keywords: Alkaline phosphatase; Ascorbic acid; Chemiluminescence; Luminol; Metal–organic frameworks.