Inhibition of dsDNA-Templated Copper Nanoparticles by Pyrophosphate as a Label-Free Fluorescent Strategy for Alkaline Phosphatase Assay

Abstract

On the basis of the inhibition of double strand DNA (dsDNA)-templated fluorescent copper nanoparticles (CuNPs) by pyrophosphate (PPi), a novel label-free turn-on fluorescent strategy to detect alkaline phosphatase (ALP) under physiological conditions has been developed. This method relies on the strong interaction between PPi and Cu(2+), which would hamper the effective formation of fluorescent CuNPs, leading to low fluorescence intensity. The ALP-catalyzed PPi hydrolysis would disable the complexation between Cu(2+) and PPi, facilitating the formation of fluorescent CuNPs through the reduction by ascorbate in the presence of dsDNA templates. Thus, the fluorescence intensity was recovered, and the fluorescence enhancement was related to the concentration of ALP. This method is cost-effective and convenient without any labels or complicated operations. The present strategy exhibits a high sensitivity and the turn-on mode provides a high selectivity for the ALP assay. Additionally, the inhibition effect of phosphate on the ALP activity was also studied. The proposed method using a PPi substrate may hold a potential application in diagnosis of ALP-related diseases or evaluation of ALP functions in biological systems.

Monitoring the activity and inhibition of alkaline phosphatase via quenching and restoration of the fluorescence of carbon dots

“…It has been reported that phosphate group containing compounds, such as the PPi hydrolysis product Pi, can inhibit the activity of ALP, as it will compete with PPi to bind with the active site of ALP [27]. Therefore, the inhibition effect of Pi on ALP activity was studied.…”

An electrochemical aptasensor for thrombin detection based on the recycling of exonuclease III and double-stranded DNA-templated copper nanoparticles assisted signal amplification

“…Since it was reported by Mokhir et al in 2010, dsDNA-templated CuNPs have attracted great attention in fluorescence analysis of biomolecules for its facile synthesis and excellent optical properties [26][27][28][29]. In this paper, we have employed electrochemical technique as a substitution of fluorescent technique to characterize the formation of dsDNA-templated CuNPs for the development of an improved new aptasensor.…”

A fluorescent probe for alkaline phosphatase via excited state intramolecular proton transfer

“…Alkaline phosphatase catalyzes dephosphorylation process of proteins, nucleic acids and small molecules, which can be found in a variety of tissues (liver, intestine, kidney, bone, and placenta) [1][2][3]. As an important diagnostic enzyme, ALP has long been identified as an important biomarker for clinical diagnostics [4].…”