In this work, we present a new microspectrometry FTIR-based biosensor for the analysis of sugar based solutions using various solvent and various types of sample handling support (SHS). We used methanol as solvent because it does not interact with infrared (IR) beam. In addition, it ensures a rapid evaporation in order to form a thin layer of targeted molecules on the conventional SHS. The later consists of a total reflective mirror (TRM). Because of methanol toxicity, we developed a new setup for aqueous samples analysis based on accelerated solvent evaporation. The achieved limit of detection (LOD) using the developed biosensor was 3 mM for both, Glucose and Fructose molecules.
This paper describes a proof of concept of a microfluidic dipole to sample cerebral fluid. It consists of a portable microfluidic probe which injects a buffer in one inlet and draws it from the other one after passing through a contact zone with the external liquid. Finite elements method modelling (FEM) shows a very stable liquid flow across the complete probing area. Furthermore, we determined that a design generating turbulence is likely to be more useful to capture brain molecules. Molecules displacement due to diffusion phenomena takes about 25 ms to diffuse over a 1 mm probe gap. Finally, our experiment showed that, to obtain a stable flow without turbulence the maximum inlet and outlet pressure is 0.05 mPa for the two tested configuration of dipole.
Wire-free power supplies provide portability, flexibility and cost efficiency as they reduces hardware complexity. Thus, in this paper we designed a portable pH sensor based on a microbial fuel cell (MFC) as a wire free energy source. Our MFCs supplied 0.127 mW to power our ultra-low power portable pH sensor. The error of the newly designed pH sensor is less than 5% when pH is between 4 and 10. Also it provides, an autonomy of 4 hours when the pH sensor is continuously used.
In this project we present a microfluidic platform with in-channel micro-electrodes for in situ screening of bio/chemical samples through a lab-on-chip system. We used a novel method to incorporate electrochemical sensors array (16x20) connected to a PCB, which opens the way for imaging applications. A 200 μm height microfluidic channel was bonded to electrochemical sensors. The micro-channel contains 3 inlets used to introduce phosphate buffer saline (PBS), ferrocynide and neurotransmitters. The flow rate was controlled through automated micro-pumps. A multiplexer was used to scan electrodes and perform individual cyclic voltammograms by a custom potentiostat. The behavior of the system was linear in terms of variation of current versus concentration. It was used to detect the neurotransmitters serotonin, dopamine and glutamate.