A Two-Photon Excited Near-Infrared Iridium(III) Complex for Multi-signal Detection and Multimodal Imaging of Hypochlorite

Abstract

Hypochlorite (ClO − ), as a type of reactive oxygen species (ROS), plays a crucial role in the process of oxidative stress and is closely related to many diseases. Thus, developing a method for detecting and imaging of ClO − with high sensitivity and selectivity is of great significance. However, the applications of most luminescent probes are limited to the fact that the excitation and emission wavelengths of them are in the visible light region rather than in the near-infrared (NIR) region. Hence, an NIR iridium(III) complex (Mul-NIRIr) with two-photon excitation is designed for the detecting and imaging of ClO − . In the presence of ClO − , the luminescent intensity and lifetime of Mul-NIRIr are remarkably enhanced. Interestingly, Mul-NIRIr also exhibits excellent electrochemiluminescence (ECL) properties, and the ECL signal is significantly enhanced with the addition of ClO − . What is more, Mul-NIRIr is also suitable for the detection and analysis ClO − by flow cytometry. Therefore, Mul-NIRIr is developed to detect multiple signals and is successfully applied to detect exogenous and endogenous ClO − in living cells with one-photon, two-photon, and phosphorescence lifetime image microscopy (PLIM). In addition, Mul-NIRIr was successfully used for imaging of ClO − in tissues and inflammatory mouse models. All of the above results indicate that Mul-NIRIr is highly effective in detecting ClO − in living systems.

Synthesis of Vitamin B1-Stabilized Gold Nanoclusters with High Quantum Yields for Application as Sensors

“…The recovered FL can be identified clearly, indicating that it can also be used for the visual detection of ClO – (inset of Figure c). The linear response range of the sensing system for ClO – is 90 nM to 27.2 μM ( R 2 = 0.9934) with a LOD of 50 nM (S/N = 3) (Figure d), which is lower or comparable to the reported works for ClO – detection via FL methods. − These results indicate that the constructed FL system based on AuNCs@VB 1 /Py has potential applications in sensing and visual detection.…”

Fine Tuning of Multiphoton AIE Emission Behavior, Organelle Targeting, and Fluorescence Lifetime Imaging of Terpyridine Derivatives by Alkyl Chain Engineering

“…The relationship between the two-photon action cross sections and the wavelength of ZA shows that the maximum value of the 2PA cross section of ZA is 102 GM under 720 nm excitation, which provides potential applications for bio-optical windows (Figure S15b). − ZA-Mex and ZA-Hex possess relatively weak two-photon excited fluorescence (Figure S16). We demonstrated the fifth-order nonlinear optical properties of ZA-Mex and ZA-Hex in the aggregation state under 1150–1550 nm fs laser excitation (Figure S17/S18).…”

Cellular imaging properties of phosphorescent iridium(iii) complexes substituted with ester or amide groups

“…2a and b), indicating an efficient uptake of the complexes by the cells. Interestingly, while complexes 2-4, like most related iridium(III) complexes, were concentrated in the cytoplasm, 24 complex 1, in contrast, showed substantial nuclear uptake, revealing whole-cell staining. The…”