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On base of the good optical properties of coumarin and fluorescein, we designed and synthesized two coumarin/fluorescein-fused fluorescent dyes ( CF dyes), which enlarged the emission wavelength and increased the Stokes shift of fluorescein moiety. The corresponding optical properties of CF dyes were investigated in detail. CF dyes could easily introduce other groups to design different functional molecules. CF dyes also exhibited rapid and sensitive responses to pH values in the range of 4.0–7.4 through the characterization of absorption and fluorescence spectra in buffer solution. More importantly, CF ethyl ester dye ( CFE dye) not only showed good cell membrane permeability and low cytotoxicity, but also had the ability to rapidly monitor mitochondrial pH changes in living cells. [ABSTRACT FROM AUTHOR]

As phototheranostic agents, carbon dots (CDs), have recently drawn considerable attention due to their excellent physicochemical properties. However, the complex synthetic route and high-cost of CDs greatly limit their practical application. To address this issue, given their nearly infinite supply from nature, Hypocrella bambusae is used as the precursor for the preparation of CDs in this study. The obtained Hypocrella bambusae CDs (HBCDs) possess good water solubility, broad absorption (350–800 nm), red-light emission (maximum peak at 610 nm), and low biotoxicity. Moreover, HBCDs can highly generate 1 O 2 (0.38) and heat (27.6%) under 635 nm laser irradiation. These excellent properties of HBCDs capacitate them to be utilized for bimodal fluorescence/photoacoustic imaging-guided synergistic photodynamic therapy (PDT)/photothermal therapy (PTT). This work provides a new candidate for tumor treatment with the combination of PDT and PTT, and explores a novel approach for the preparation of CD-based phototheranostic agents with natural biomass as raw carbon sources. [ABSTRACT FROM AUTHOR]

The pH homeostasis of Golgi plays a vital role in maintaining normal cell functions. An effective near-infrared fluorescent probe that can sense pH changes in Golgi apparatus is of great significance. Here, a Golgi-targeting fluorescent probe (Golgi-hNR) based on a rhodamine derivative is presented to show a highly sensitive response to pH variations. Golgi-hNR displays a conspicuous pH-dependent behavior at 664 nm from pH 7.4–3.0 with a remarkable fluorescence off-on response. The pKa value of Golgi-hNR is measured to be 3.62. Confocal fluorescence imaging reveals that Golgi-hNR diffuses into Golgi with high selectivity. Using Golgi-hNR , we have successfully visualized real-time tracking of Golgi pH variations for medical therapy in living cells. • An effective near-infrared fluorescent probe (Golgi-hNR) based on rhodamine is presented to sense pH variations. • Golgi-hNR displays a conspicuous pH-dependent behavior with a remarkable fluorescence off-on response. • Golgi-hNR was successfully visualized for real-time tracking of Golgi pH variations for medical therapy in cells. [ABSTRACT FROM AUTHOR]

Benzopyran nitrile dyes cannot be used as qualified photosensitizers due to the low quantum yield of triplet state. The benzopyran derivatives containing selenium instead of oxygen atom based on the heavy atom effect are expected to become potential agents for photodynamic therapy. In this paper, a series of selenium-containing photosensitizers (PS X) were prepared according to this strategy. PS X can effectively produce both singlet oxygen and superoxide anions upon laser irradiation. PS X exhibited the emission wavelength at 500–800 nm and near-infrared (NIR) fluorescence imaging in HeLa cells. Excellent biocompatibility and phototoxicity further indicated that PS X could be used as efficient photosensitizers for NIR fluorescence imaging and photodynamic therapy. Four novel selenium-containing photosensitizers (PS X) have been synthesized through a strategy of introducing Se into the dye core. PS X can serve as effective photosensitizers for NIR fluorescence imaging and photodynamic therapy. [Display omitted] • Four selenium-containing photosensitizers (PS X) were prepared by introducing Se into the dye core. • PS X can effectively produce both singlet oxygen and superoxide anions upon laser irradiation. • PSx exhibited near-infrared fluorescence imaging and efficient photodynamic therapy in HeLs cells. [ABSTRACT FROM AUTHOR]