10.1016/j.cclet.2013.11.024
The research presented in the scholarly article focuses on the development of a highly selective two-photon fluorescent probe, ADNO (2-(α-(3,4-diaminophenoxy)acetyl)-6(dimethylamino)naphthalene), for imaging nitric oxide (NO) in living cells. The probe is designed based on the photoinduced electron transfer (PET) mechanism, utilizing o-phenylenediamine as the NO-sensitive fluorescence modulator and 2-acetyl-6-(dimethylamino)naphthalene (Acedan) as the two-photon fluorophore. The detection of NO is achieved by monitoring the alteration of electron-donating capacity of the o-phenylenediamine moiety, which quenches the fluorescence of Acedan but is reversed in the presence of NO due to the transformation into benzotriazole, thus reviving fluorescence. The probe's rapid response, remarkable fluorescent enhancement, and excellent chemoselectivity for NO over other reactive oxygen/nitrogen species (ROS/RNS) and common metal ions were demonstrated through a series of experiments. These experiments included the synthesis of ADNO, its spectral characterization, and its application in fluorescence imaging of NO in living cells using both one-photon microscopy (OPM) and two-photon microscopy (TPM). The study also assessed the probe's performance at various pH levels and its stability and selectivity in the presence of different ROS/RNS and metal ions. The research utilized various analytical techniques such as NMR, mass spectrometry, UV–vis, and fluorescence spectroscopy to characterize the probe and evaluate its performance.