Ye Ying

Facile construction of a polydopamine-based hydrophobic surface for protection of metals against corrosion

Metal surfaces with a hydrophobic feature, which could prevent percolation of water droplets and improve their resistance against corrosion, have attracted extensive interest. In this work, we demonstrated a method to prepare a hydrophobic copper surface by coating polydopamine (PDA), and modifying with 1-dodecanethiol (1-DT). Surface hydrophobicity was evaluated by contact angle analysis. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), near infrared (NIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) were employed to understand the structure and composition of the resultant coating at the metal surface. The inhibition efficiency of the optimal hydrophobic surface in 3 wt% NaCl aqueous solution, explored by using electrochemical measurements, was 95.3%, which was due to synergy effects of PDA and 1-DT. The promising inhibition of copper corrosion was also validated by scanning electron microscopy observation.

Dentritic CuPtPd Catalyst for Enhanced Electrochemical Oxidation of Methanol

The CuPtPd catalyst is designed and synthesized successfully via directly reducing metal ions. The composition, morphology, and structure of the as-prepared CuPtPd nanohybrids are characterized by scanning electron microscopy and transmission electron microscopy, energy-dispersive spectrometry, selected-area electron diffraction, X-ray diffraction, and inductively coupled plasma atomic emission spectrometry. By comparison of the electrocatalytic properties of the ternary CuPtPd catalyst with bimetallic catalysts, we find that ternary nanocomposites perform better electrocatalytic and antipoisoning activity toward oxidation of methanol. The catalytic mass activity of the CuPtPd nanoparticles is 5.51-fold of commercial Pd black and 12.1-fold of Pt black.

Electrospun CuO-Nanoparticles-Modified Polycaprolactone @Polypyrrole Fibers: An Application to Sensing Glucose in Saliva

A non-invasive method for detecting glucose is pursued by millions of diabetic patients to improve their personal management of blood glucose. In this work, a novel CuO nanoparticles (NPs) decorated polycaprolactone@polypyrrole fibers modified indium-tin oxide (denoted as CuO/PCL@PPy/ITO) electrode has been fabricated by electrospinning combined with the electrodeposition method for non-enzymatic detection of glucose in saliva fluid. The electrospun composite fibers exhibit high sensitivity for the glucose detection. The synergistic effect between CuO and PPy together with the unique three-dimensional net structure contributes the reliable selectivity, good test repeatability, large-scale production reproducibility in massive way, the reasonable stability and a high catalytic surface area to the sensor. Quantitative detection of glucose is determined in the linear range from 2 μM to 6 mM and the lowest detection limit is 0.8 μM. The CuO/PCL@PPy/ITO electrode shows potential for the non-invasive detection of salivary glucose.

Hollow Echinus-like PdCuCo Alloy for Superior Efficient Catalysis of Ethanol

Large-scale preparation of hollow echinus-like PdCuCo alloy nanostructures (HENSs) with a high surface area-to-volume ratio, rich active sites, and relatively efficient catalytic activity has attracted considerable research interest. Herein, we present an economic and facile approach to synthesize HENSs by galvanic exchange reactions using Co nanospheres as sacrificial templates. Moreover, the catalytic activity could be adjusted via changing the composition of the catalyst. The composition, morphology, and crystal structure of the as-obtained nanomaterials are characterized by various techniques, such as inductively coupled plasma atomic emission spectrometry, transmission electron microscopy, and X-ray diffraction. Electrochemical catalytic measurement results prove that the Pd75Cu8Co3 catalyst obtained under optimal preparation conditions exhibits 10-fold higher activity for ethanol oxidation in comparison with the commercially available 20% Pd/C catalyst. The eminent performance of the Pd75Cu8Co3 electrochemical catalyst could be ascribed to the peculiar echinus-like nanostructures.

4-Phenylpyrimidine monolayer protection of a copper surface from salt corrosion

4-Phenylpyrimidine (4-PPM) containing N heteroatoms can easily form compact and uniform layers on metallic surfaces. In this work, the protection of a copper surface from corrosion in 3 wt% NaCl by a 4-PPM layer was investigated by electrochemical impedance spectroscopy (EIS) and polarization methods. Under optimum conditions, the inhibition efficiency of a 4-PPM layer for copper corrosion reached 83.2%. Raman analysis in conjunction with calculations using density functional theory (DFT) based on the B3LYP/LANL2DZ basis set suggested that the 4-PPM molecule anchored on the copper surface via the N1 atom to construct a uniform layer.

Thiol–Disulfide Exchange Reaction for Cellular Glutathione Detection with Surface-Enhanced Raman Scattering

Abnormal glutathione (GSH) levels are related to several diseases, including cancer. In this paper, surface-enhanced Raman spectroscopy (SERS) based on a 2-(pyridyldithio)ethylamine (PDEA)-modified AgNPs@Si wafer is proposed for intracellular GSH detection. PDEA plays multifunctional roles in the method, including the participation in the thiol-disulfide exchange reaction and the contribution of a great SERS signal reporter. With the addition of GSH, the disulfide bond of PDEA will be broken, releasing the pyridine ring in PDEA and resulting in a signal-off SERS response. The developed specific reaction-based SERS assay can detect GSH levels as low as 2.5 × 10-7 M. Subsequently, we employed this method to evaluate cellular GSH levels and found that the levels in cancer cells are higher than those in normal cells. The PDEA-modified AgNPs@Si-based SERS protocol demonstrates good selectivity and high sensitivity, as well as robustness, which is suitable to evaluate cellular GSH levels.

Facile synthesis of Au/Al2O3 nanocomposites for improving the detection sensitivity of adenosine triphosphate

Alumina is widely recognized as chemically inert, and resistant to oxidation and high temperature. In this study, Au/Al2O3 nanocomposites (NCs) were prepared by a facile method and were used as a surface enhanced Raman scattering (SERS) substrate for detection of adenosine triphosphate (ATP). This Au/Al2O3-based SERS substrate demonstrated good sensitivity with the lowest detectable concentration of 5 × 10−9 M for ATP and a good linear relationship ranging from 5 × 10−5 to 5 × 10−9 M. The strategy of improvement of SERS detection sensitivity for ATP was based on the consideration of ATP captured by such SERS substrate via chelation of aluminum and phosphates, which was validated by X-ray photoelectron spectroscopy. In addition, alumina as a supporting material could be expected to prolong the stability of such a SERS substrate.