RETRACTED: An acridone-derived fluorescent off-on probe for detection and in vivo imaging of nitroreductase

• Published in: Frontiers in materials 2023-07, Vol.10
• Main Authors: Liu, Meicen, Chen, Guanyu, Xu, Lilan, Chen, Tingting, Chen, Wenqian, Chen, Jinghua, Zhang, Xi
• Format: Article
• Language: English
• Subjects: acridone derivate; fluorescence imaging; nitroreductase; two-photon; zebrafish
• ISSN: 2296-8016; 2296-8016
• DOI: 10.3389/fmats.2023.1220382

Understanding the functions of enzymes in various physiological processes is important, but the design of signaling probes for fast analysis of enzymatic activity is particularly challenging. Herein, a fluorescence-enhanced probe, 10-methyl-2-nitro-acridone (MNA), was synthesized and applied to analyze nitroreductase (NTR) activity in vitro and in vivo . The detection mechanism is based on the nitro group in MNA reacting toward NTR with high reactivity and generating 10-methyl-2-amino- acridone (MAA) accompanied by an obvious fluorescence signal enhancement at 525 nm emission. The probe shows low cytotoxicity, fast response, and high selectivity and sensitivity with a limit of detection as low as 150 ng·mL −1 . The probe was also employed for two-photon fluorescence imaging of NTR in zebrafish in vivo revealing the distribution of NTR. Versus existing NTR probes, the proposed probe shows favorable analytical performance including near-infrared light excitation with no other byproducts produced after the reaction. The superior properties of this signaling probe allow it to become a fluorescence imaging candidate in other biosystems.