Improvement of electrochemical detection of transthyretin synthetic peptide and its amino acids on carbon electrodes: Glassy carbon versus amorphous carbon nitride a-CNx

Release and Detection of microRNA by Combining Magnetic Hyperthermia and Electrochemistry Modules on a Microfluidic Chip

The heating of a biologic solution is a crucial part in an amplification process such as the catalytic detection of a biological target. However, in many situations, heating must be limited in microfluidic devices, as high temperatures can cause the denaturation of the chip components. Local heating through magnetic hyperthermia on magnetic nano-objects has opened the doors to numerous improvements, such as for oncology where a reduced heating allows the synergy of chemotherapy and thermotherapy. Here we report on the design and implementation of a lab on chip without global heating of samples. It takes advantage of the extreme efficiency of DNA-modified superparamagnetic core-shell nanoparticles to capture complementary sequences (microRNA-target), uses magnetic hyperthermia to locally release these targets, and detects them through electrochemical techniques using ultra-sensitive channel DNA-modified ultramicroelectrodes. The combination of magnetic hyperthermia and microfluidics coupled with on-chip electrochemistry opens the way to a drastic reduction in the time devoted to the steps of extraction, amplification and nucleic acids detection. The originality comes from the design and microfabrication of the microfluidic chip suitable to its insertion in the millimetric gap of toric inductance with a ferrite core.

Dispersity control and anti-corrosive performance of graphene oxide modified by functionalized nanosilica in waterborne polyurethane

Graphene oxide (GO) is expected to be used in the field of waterborne polyurethane (WPU) anti-corrosive coatings due to its excellent barrier property, but the poor dispersibility of GO limits its application. The hydrophilic modification of GO, although improving its dispersity, will greatly reduce its anti-corrosive property. Here, a new method is provided to avoid seeking an appropriate modifier blindly. Via the interaction between the epoxy group and amine group, the aminated GO (NGO) can be modified by (3-glycidyloxypropyl) trimethoxysilane (KH560) functionalized-silica (f-SiO₂) nanoparticles, while the f-SiO₂ is affected by KH560 due to its relatively hydrophobic alkyl side chain. Consequently, the hydrophobicity of the f-SiO₂ modified NGO (f-SGO) can be regulated just by adjusting the amount of KH560, thereby achieving the balance of excellent dispersibility and anti-corrosive performance of the f-SGO nanosheets in the WPU. The electrochemical impedance and potentiodynamic polarization results showed that the anti-corrosive performance of the WPU hybrid was greatly improved by adding the appropriate amount of f-SGO. This research provides a new idea for GO application in waterborne coatings.

Design principles and fundamental understanding of biosensors for amyloid-β detection

Aβ as biomarker in Alzheimer’s disease (AD) drives the significant research efforts for developing different biosensors with different sensing strategies, materials, and mechanisms for Aβ detection.