Facile preparation of bifunctional monolayers through diazonium grafting and "click" postfunctionalization: A first step towards efficient aptasensing interfaces.

Herein, we present an efficient approach for developing electrochemical aptasensing interfaces, by "click" postfunctionalization of phenylethynyl-grafted glassy carbon substrates with mixed monolayers containing biorecognition elements and phosphorylcholine zwitterionic groups. Typically, controlling the composition of multicomponent surface layers by grafting from a mixture of aryldiazonium salts is challenging due to differences in their chemical reactivity. Our approach circumvents this issue by employing the electrochemical reduction of a single aryldiazonium salt containing a silyl-protected alkyne group followed by deprotection, to create phenylethynyl monolayers which can subsequently accommodate the concurrent immobilization of bioreceptors and zwitterionic groups through "click" postfunctionalization.

Synthesis and evaluation of poly(propylene fumarate)-grafted graphene oxide as nanofiller for porous scaffolds.

In an effort to obtain porous scaffolds with improved mechanical properties and biocompatibility, the current study discusses nanocomposite materials based on poly(propylene fumarate)/-vinyl pyrrolidone(PPF/NVP) networks reinforced with polymer-modified graphene oxide (GO@PPF). The GO@PPF nanofiller was synthesized through a facile and convenient surface esterification reaction, and the successful functionalization was demonstrated by complementary techniques such as FT-IR, XPS, TGA and TEM. The PPF/NVP/GO@PPF porous scaffolds obtained using NaCl as a porogen were further characterized in terms of morphology, mechanical properties, sol fraction, and degradability.

Critical Design Factors for Electrochemical Aptasensors Based on Target-Induced Conformational Changes: The Case of Small-Molecule Targets.

Nucleic-acid aptamers consisting in single-stranded DNA oligonucleotides emerged as very promising biorecognition elements for electrochemical biosensors applied in various fields such as medicine, environmental, and food safety. Despite their outstanding features, such as high-binding affinity for a broad range of targets, high stability, low cost and ease of modification, numerous challenges had to be overcome from the aptamer selection process on the design of functioning biosensing devices. Moreover, in the case of small molecules such as metabolites, toxins, drugs, etc.

Improving the Voltammetric Determination of Hg(II): A Comparison Between Ligand-Modified Glassy Carbon and Electrochemically Reduced Graphene Oxide Electrodes.

A new thiosemicarbazone ligand was immobilized through a Cu(I)-catalyzed click reaction on the surface of glassy carbon (GC) and electrochemically reduced graphene oxide (GC-ERGO) electrodes grafted with phenylethynyl groups. Using the accumulation at open circuit followed by anodic stripping voltammetry, the modified electrodes showed a significant selectivity and sensibility for Hg(II) ions. A detection limit of 7 nM was achieved with the GC modified electrodes.

Cellulose acetate/layered double hydroxide adsorptive membranes for efficient removal of pharmaceutical environmental contaminants.

The increasing amount of residual pharmaceutical contaminants in wastewater has a negative impact on both the environment and human health. In the present study, we developed new cellulose acetate/Mg-Al layered double hydroxide (Mg-Al LDH) nanocomposite membranes as an efficient method to remove pharmaceutical substances from wastewater. The morphology, porosity, surface properties and thermal stability of nanocomposite membranes containing various amounts of nanofiller were evaluated by scanning electron microscopy (SEM), X-ray microtomography (μCT), contact angle measurements and thermogravimetric analysis (TGA).