In Situ Colorimetric Recognition of Melamine Based on Thymine Derivative-Functionalized Gold Nanoparticle

A simple, fast, and convenient colorimetric sensing system is presented for melamine recognition in milk samples by thymine-derivative- (<b>NT</b>-) decorated gold nanoparticles (AuNPs), based on the complementary hydrogen bond between thymine and melamine, wherein the introduction of melamine causes a rapid and obvious red-to-blue color change. Therefore, the melamine content in milk can be qualitatively recognized by the naked eye and quantitatively measured by measuring absorbance. <b>NT</b>-AuNPs show excellent selectivity to melamine against any other tested molecules, anions, and metal ions, as well as very good sensitivity that can distinguish melamine-contaminated milk from safe milk with a limit of detection of 3.5 nM

Tuning the Electrochemiluminescence Color by Potential: Design of a Series of Heterodinuclear Ir/Ru Labels

A series of heterodinuclear complexes [(bpy)₂Ru­(bpy)­(CH₂)<i>_n</i>(bpy)­Ir­(df-ppy)₂]³⁺ (<b>1</b>, where bpy is 2,2′-bipyridyl, df-ppy is 2-(2,4-difluorophenyl)­pyridine, and <i>n</i> = 10, 12, 14) have been designed and synthesized. Both red (from the Ru moiety) and green (from the Ir moiety) electrochemiluminescence (ECL) can be acquired simultaneously thorough alternation of the scanning potentials; especially, a good linear calibration curve between the ECL intensity ratio (<i>I</i>_Ru/<i>I</i>_Ir) and the scanning potential can be reached over a potential range from 0.55 to 1.6 V. All of this provides a general methodology for developing electrochemistry induced light-emitting devices and a ratiometric ECL detection method

Microenvironment-Sensitive Fluorescent Dyes for Recognition of Serum Albumin in Urine and Imaging in Living Cells

A series of microenvironment-sensitive fluorescent dyes, <b>SA1</b>–<b>4</b>, have been presented, which can light up human serum albumin (HSA) in aqueous media and solid state with colorful emissions as well as dramatic fluorescence enhancements respectively, based on twisted intramolecular charge transfer and molecular rotor strategy. These microenvironment-sensitive <b>SA1</b>–<b>4</b> exhibited excellent fluorescent capabilities in the fast, convenient, selective, and sensitive recognition of HSA, especially in the quantitative albumin assay in human urine for assessment of kidney function and diagnosis of renal disease. Moreover, <b>SA1</b>–<b>4</b>/HSA complexes could be applied in fluorescence imaging in living cells

An “Enhanced PET”-Based Fluorescent Probe with Ultrasensitivity for Imaging Basal and Elesclomol-Induced HClO in Cancer Cells

Reactive oxygen species (ROS) and cellular oxidant stress have long been associated with cancer. Unfortunately, the role of HClO in tumor biology is much less clear than for other ROS. Herein, we report a BODIPY-based HClO probe (<b>BClO</b>) with ultrasensitivity, fast response (within 1 s), and high selectivity, in which the pyrrole group at the <i>meso</i> position has an “enhanced PET” effect on the BODIPY fluorophore. The detection limit is as low as 0.56 nM, which is the highest sensitivity achieved to date. <b>BClO</b> can be facilely synthesized by a Michael addition reaction of acryloyl chloride with 2,4-dimethyl­pyrrole and applied to image the basal HClO in cancer cells for the first time and the time-dependent HClO generation in MCF-7 cells stimulated by elesclomol, an effective experimental ROS-generating anticancer agent

Gold Nanoparticle-Based Colorimetric Recognition of Creatinine with Good Selectivity and Sensitivity

A gold nanoparticle-based colorimetric sensor for the determination of creatinine was developed as an important index for early diagnosis of kidney function and corresponding renal diseases. Because of the unique synergistic coordination capability of adenosine and creatinine with Ag⁺ on a particle surface, our system exhibits an excellent selectivity to creatinine among various ions and biomolecules. There are good linear relationships of absorption changes (<i>A</i>_{630 nm/520 nm}) over creatinine concentrations, so both colorimetric qualitative detection by the naked eye and quantitative determination by UV–vis spectrometer could be realized with an excellent limit of detection compared with that of other methods. Finally, by testing creatinine in practical samples, such as urine mimic and bovine serum, good recoveries were obtained with proper relative standard deviations

Grafting PEI-1.8 to CS via CDI to synthesize CS-<i>g</i>-PEI in [BMIM]Ac.

<p>Grafting PEI-1.8 to CS via CDI to synthesize CS-<i>g</i>-PEI in [BMIM]Ac.</p

Systematic Analysis of the Lysine Acetylome in <i>Vibrio parahemolyticus</i>

Lysine acetylation of proteins is a major post-translational modification that plays an important regulatory role in almost every aspect of cells, both eukaryotes and prokaryotes. Vibrio parahemolyticus, a model marine bacterium, is a worldwide cause of bacterial seafood-borne illness. Here, we conducted the first lysine acetylome in this bacterium through a combination of highly sensitive immune-affinity purification and high-resolution LC–MS/MS. Overall, we identified 1413 lysine acetylation sites in 656 proteins, which account for 13.6% of the total proteins in the cells; this is the highest ratio of acetyl proteins that has so far been identified in bacteria. The bioinformatics analysis of the acetylome showed that the acetylated proteins are involved in a wide range of cellular functions and exhibit diverse subcellular localizations. More specifically, proteins related to protein biosynthesis and carbon metabolism are the preferential targets of lysine acetylation. Moreover, two types of acetylation motifs, a lysine or arginine at the +4/+5 positions and a tyrosine, histidine, or phenylalanine at the +1/+2 positions, were revealed from the analysis of the acetylome. Additionally, protein interaction network analysis demonstrates that a wide range of interactions are modulated by protein acetylation. This study provides a significant beginning for the in-depth exploration of the physiological role of lysine acetylation in V. parahemolyticus

FTIR spectra of CS and CS-<i>g</i>-PEI copolymers with different grafting degrees.

<p>FTIR spectra of CS and CS-<i>g</i>-PEI copolymers with different grafting degrees.</p

Encapsulated Dye/Polymer Nanoparticles Prepared via Miniemulsion Polymerization for Inkjet Printing

Owing to its simple operation and minimal generation of pollutants, miniemulsion polymerization has attracted increasing interest in the field of inkjet printing. In this study, different dyes were encapsulated with styrene-<i>co</i>-butyl acrylate copolymers via miniemulsion polymerization. The encapsulated dye/polymer nanoparticles were spherical with an apparent shell–core structure, narrow size distributions, and good thermal stability. These nanoparticles were used as miniemulsion inks that could remain unchanged with good photostability for a long time. The miniemulsion ink was successfully applied to inkjet printing on paper with bright colors and good fluency, and the dyeing of cotton fabrics indicated that these nanoparticles possessed good rubbing and washing fastness. All of these results suggest that the miniemulsion ink is a potential substitute for inks based on traditional dyes in inkjet printing

Fluorescence images of HEp-2 cells exposed to the polyplexes (N/P = 6) after transfection of 24 h.

<p>(a) CS/pDNA, (b) CS-<i>g</i>-PEI-0.9/pDNA, (c) CS-<i>g</i>-PEI-1.8/pDNA, (d) CS-<i>g</i>-PEI-4.5/pDNA, (e) CS-<i>g</i>-PEI-9.0/pDNA, (f) PEI-1.8/pDNA and (g) PEI-25, using pGFP-N2 as report gene. Relative quantitative GFP expression efficiency of polyplexes was shown (h).</p