Showing papers by "Hui Wei published in 2015"

Ratiometric electrochemical sensor for effective and reliable detection of ascorbic acid in living brains.

Abstract: The in vivo detection of ascorbic acid (AA), one of the physiologically important cerebral neurochemicals, is critical to probe and understand brain functions. Electrochemical sensors are convenient for AA detection. However, conventional electrochemical sensors usually suffer from several challenges, such as sluggish electron transfer kinetics for AA oxidation and poor reproducibility. To address these challenges, here we report ratiometric electrochemical sensors for effective and reliable detection of AA in living brains. The sensors were constructed by immobilizing preassembled thionine/Ketjen black (KB) nanocomposites onto glassy carbon (GC) electrodes or carbon fiber microelectrodes (CFMEs). The KB in the rationally functionalized nanocomposites efficiently facilitated AA oxidation at a relatively negative potential (∼−0.14 V) without particular physical or chemical pretreatment, forming the basis of selective measurement of AA. With a well-defined and reversible pair of redox wave at −0.22 V, the a...

A “turn on” fluorescent probe for heparin and its oversulfated chondroitin sulfate contaminant

Abstract: Designing “turn on” fluorescent probes for heparin (Hep), a widely used anticoagulant in clinics, is of great importance but remains challenging. By introducing a Hep specific binding peptide AG73 to a typical aggregation induced emission (AIE) fluorogen, tetraphenylethene (TPE), a sensitive and selective “turn on” fluorescent probe named TPE-1 for Hep was developed. TPE-1 was able to detect Hep in a wide pH range of 3–10 without obvious interference from tested anions and biomolecules, especially Hep analogues known as chondroitin sulfate (Chs) and hyaluronic acid (HA). The detection limit of Hep sensing was 3.8 ng mL−1, which was far below the clinically demanded concentration of Hep. The probe was applicable to both unfractionated Hep and low molecular weight Hep, the two main heparin products clinically used. Besides, the fluorescence of Hep bound TPE-1 can be turned off via sequential treatment with heparinases. Importantly, this phenomenon allows us to develop an enzyme assisted strategy for “turn on” sensing of oversulfated chondroitin sulfate (OSCS) with a detection limit of 0.001% (w%), which is the main contaminant in Hep and may cause severe adverse reactions including death.

Protein‐ and Peptide‐directed Approaches to Fluorescent Metal Nanoclusters

Abstract: Fluorescent metal nanoclusters (FMNCs), one of the promising functional nanomaterials, have aroused great interest in diverse areas due to their unique characteristics, such as ultrasmall size, high fluorescence, excellent photophysical and chemical stability, good biocompatibility, and tuneable emissions. Many methods have been developed to prepare the FMNCs. Among them, the biomolecule-directed approach, which could produce FMNCs with high water-solubility, good biocompatibility, enhanced fluorescence, and rich surface chemistry for conjugation has attracted enormous attention. In this review, we highlight the substantial progress in protein- and peptide-directed approaches to varieties of FMNCs. The synthetic protocols and potential formation mechanisms are well summarized. Selected key applications, ranging from biological and chemical detection to cellular and in vivo imaging, are also discussed. Finally, the current challenges, as well as future perspectives, are briefly discussed. The lessons from these case studies would provide a valuable guide to designing nanomaterials with desired or even personalized functions in the future.

Protein‐ and Peptide‐Directed Approaches to Fluorescent Metal Nanoclusters

Abstract: Fluorescent metal nanoclusters (FMNCs), one of the promising functional nanomaterials, have aroused great interest in diverse areas due to their unique characteristics, such as ultrasmall size, high fluorescence, excellent photophysical and chemical stability, good biocompatibility, and tuneable emissions. Many methods have been developed to prepare the FMNCs. Among them, the biomolecule-directed approach, which could produce FMNCs with high water-solubility, good biocompatibility, enhanced fluorescence, and rich surface chemistry for conjugation has attracted enormous attention. In this review, we highlight the substantial progress in protein- and peptide-directed approaches to varieties of FMNCs. The synthetic protocols and potential formation mechanisms are well summarized. Selected key applications, ranging from biological and chemical detection to cellular and in vivo imaging, are also discussed. Finally, the current challenges, as well as future perspectives, are briefly discussed. The lessons from these case studies would provide a valuable guide to designing nanomaterials with desired or even personalized functions in the future.