Analysis of the evolution of the detection limits of electrochemical nucleic acid biosensors II.

This critical review of electrochemical biosensors allowing direct detection of nucleic acid targets reports on different transduction pathways and their latest breakthroughs. A classification of the various strategies based on the nature of the electrochemical transduction is established to emphasize the efficiency of each of them. It provides an overall picture of the detection limit of the various approaches developed during the last two decades.

Electrochemical Impedance Spectroscopy in a Droplet of Solution for the Investigation of Liquid/Solid Interface.

The local electrochemical behavior of a solid-liquid interface can be studied by electrochemical impedance spectroscopy (EIS). The investigated surface area can be delimited by adding a drop of solution, which forms an interface between the liquid drop and the working electrode, and performing the measurements inside. The size of the drop must be sufficiently small for a simultaneous wettability characterization (from the contact angle measurement) and appropriately large so that wettability is not influenced by the presence of the working and the counter electrode inserted in the droplet.

Electrodeposition and Characterization of Hydroxyapatite on TiN/316LSS.

The deposition of TiN on stainless steel substrates may improve the stability and compatibility of this material with bone, which may be advantageously exploited for the elaboration of advanced pros- thetic devices. In this work, TiN-coated 316LSS (by way of DC magnetron sputtering) was used as a starting material for investigating the electrochemical post-deposition of hydroxyapatite (HAp) which has a composition close to that of bone. Electrodeposition was carried out starting from an aqueous medium containing solubilized Ca(NO3)2 and NH4H2PO4 in the presence of H2O2.

The Electrochemical Behavior of TiN/316LSS Material in Simulated Body Fluid Solution.

We report on the fabrication and the electrochemical behavior of TiN film on the 316L stainless steel (316LSS) material in simulated body fluid (SBF) solution for implant application. The characterization results indicate that the coated TiN is completely crystalline with (111) crystal orientation. Electrochemical results of 316LSS and TiN/316LSS material after 21 days of immersion in SBF show that the durability of the TiN/316LSS is much higher than that of 316LSS, which registers a very low corrosion current density (about tens of nA cm(-2)).

Preparation and Properties of Ethylene Vinyl Acetate Copolymer/Silica Nanocomposites in Presence of EVA-g-Acrylic Acid.

Here we report a facile approach to enhance the dispersibility of ethylene vinyl acetate copolymer (EVA)/silica nanocomposites (for the EVA/silica nanocomposites and interaction between silica nanoparticles (nanosilica) and EVA by adding EVA-g-acrylic acid (EVAgAA) as a compatibilizer, which was formed by grafting acrylic acid onto EVA chains with the aid of dicumyl peroxide). The above nanocomposites with and without EVAgAA were prepared by melt mixing in a Haake intermixer with different contents of silica and EVAgAA. Their structure and morphology were characterized by Fourier transform infra-red (FT-IR) spectroscopy, field emission scanning electron microscopy (FE-SEM), and the mechanical, rheological, dielectrical, and flammability properties of the nanocomposites were also investigated.