We have prepared graphene quantum dot-europium(III) complex composites by noncovalently connecting chelating ligands dibenzoylmethane (DBM) and 1,10-phenanthroline (Phen) with graphene quantum dots (GQDs) first, followed by coordination to Eu(III). The resulting composites are well water-soluble and display red fluorescence of high color purity. The composites were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction. Aqueous solutions of the composites under 365 nm excitation display fluorescence with a peak at 613 nm and a quantum yield as high as 15.5 %. The good water solubility and stable photoluminescence make the composites very different from other Eu(III)-based coordination complexes. The composites are cell viable and can be used to label both the cell membrane and the cytoplasm of MCF-7 cells. They are also shown to act as bioprobes for in-vivo localization of tumorous tissue. In our perception, such composites are expected to possess wide scope because of the many functionalizations that are possible with GQDs.
A simple and highly sensitive electrochemiluminescent immunosensor based on nanocomposite architecture of the one-pot synthesized carbon nanodots and Nafion composite film was proposed for the detection of α-fetoprotein. 相似文献
Current microfluidic paper-based devices lack crucial components for fluid manipulation. We created a fluidic diode fabricated entirely on a single layer of paper to control the wicking of fluids. The fluidic diode is a two-terminal component that promotes or stops wicking along a paper channel. We further constructed a trigger and a delay valve based on the fluidic diode. Furthermore, we demonstrated a high-level functional circuit, consisting of a diode and a delay valve, to manipulate two fluids in a sequential manner. Our study provides new, transformative tools to manipulate fluid in microfluidic paper-based devices. 相似文献
The increase and spread of Gram‐negative bacteria that resistant are to almost all currently available β‐lactam antibiotics is a major global health problem. The primary cause for drug resistance is the acquisition of metallo‐β‐lactamases such as metallo‐β‐lactamase‐1 (NDM‐1). The fungal natural product aspergillomarasmine A (AMA), a fungal natural product, is an inhibitor of NDM‐1 and has shown promising in vivo therapeutic potential in a mouse model infected with NDM‐1‐expressing Gram‐negative bacteria. The first total synthesis and stereochemical configuration reassignment of aspergillomarasmine A is reported. The synthesis highlights a flexible route and an effective strategy to achieve the required oxidation state at a late stage. This modular route is amenable to the efficient preparation of analogues for the development of metallo‐β‐lactamase inhibitors to potentiate β‐lactam antibiotics. 相似文献
