Mn 2+ -Mediated Modulation of PfAgo Activity for Biosensing.

Argonaute (Ago) as a powerful enzyme has provided new insights into biosensing due to its programmability, high sensitivity, and user-friendly operation. However, current strategies mainly rely on phosphorylated guide DNA to modulate the cleavage activity of Ago, which are limited in versatility and simplicity. Herein, we reported Mn 2+ -enhanced cleavage activity of Ago and employed Mn ions with variable valence to regulate the activity of Pyrococcus furiosus Ago (PfAgo) for biosensing applications. The conversion of Mn ions with different valence states through MnO 2 nanoflowers enables the sensitive detection of ascorbic acid, alkaline phosphatase, and arsenic with limits of detection of 2.5 nmol L -1 , 0.009 U L -1 , and 0.4 ng mL -1 , respectively. We further developed a PfAgo-based immunoassay that allows for the detection of diverse targets, thus providing a promising toolbox to broaden PfAgo-based sensors into versatile bioanalytical and biomedical applications. This article is protected by copyright. All rights reserved.