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

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.