invivo imaginganddetectionofnitroreductaseinzebra ? shbyanewnear-infrared ? uorescenceoff – onprobe

Short communication in vivo imaging and detection of nitroreductase in zebrafish by a new near-infraredfluorescence off–on probe Zhao Li a , Xinyuan He a , Zhe Wang a , Ronghua Yang b , Wen Shi a , Huimin Ma a,n a Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China b State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410082, China article info Article history: Received 9 June 2014 Received in revised form 8 July 2014 Accepted 9 July 2014 Available online 16 July 2014 Keywords: Nitroreductase Near-infraredfluorescence probe in vivo imaging Zebrafish abstract A new near-infraredfluorescence off–on probe is developed and applied tofluorescence imaging of nitroreductase in zebrafish in vivo. The probe is readily prepared by connecting 4-nitrobenzene as a quenching and recognizing moiety to a stable hemicyanine skeleton that can be formed via the decomposition of IR 780. Thefluorescence off–on response of the probe to nitroreductase is based on the enzyme-catalyzed reduction of the 4-nitrobenzene moiety, followed by the 1,6-rearrangementelimination and the fluorophore release. Compared with the existing nitroreductase probes, the proposed probe exhibits superior analytical performance such as near-infraredfluorescence emission over 700 nm as well as high selectivity and sensitivity, with a detection limit of 14 ng/mL. More importantly, the probe has been successfully applied to visualize the distribution of nitroreductase in living zebrafish in vivo, revealing that nitroreductase might mainly exist in zebrafish yolk sac. The superior properties of the probe make it of great potential use in other biosystems andin vivo studies. &2014 Elsevier B.V. All rights reserved.