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We investigated the possibility to grow molecularly porous amino-silane layers on glass-like substrates. The goal of this work is to show that it is possible to substantially increase the sensitivity of a fluorescence sensor by adjusting the functionalization strategy. Two methods are studied, one using APTMS only and another one using both APTMS and APDMS. We show that, using the second method, sensor sensitivity is improved by a factor of about 5. In order to demonstrate this, we applied the technique to the grafting of fluorescein in order to build a fluorescence pH sensor.

This article presents a novel low cost force sensing platform for the mechanical characterisation of human oocytes. This platform is compatible with the specific context of Assisted Reproductive Technology (ART). The oocyte is placed inside a standard Petri dish filled with a culture medium. It is immobilized using a holding pipette. The disposable parts used to mechanically test each oocyte are made of glass. This configuration is very similar to the one used in IntraCytoplasmic Sperm Injection protocol excepted that the injection pipette is replaced by a glass indenter. This platform uses two passive and linear magnetic springs to measure the nanoforce applied to the oocyte. The stabilisation of the unstable magnetic springs is passively achieved using the reaction force generated by the compressed oocyte. Some preliminary results obtained with an experimental platform are presented. The global magnetic stiffness of the indenter, evaluated by simulation and experimentally identified, is about 0.0013 N m−1.

In the field of blood transfusion, there is a need to improve the bedside pre-transfusion ABO compatibility test. In France, this test is mandatory for each red cell concentrates transfusion. It is performed manually and serious transfusion accidents still occur, principally due to human errors. Therefore, an automated ABO compatibility test is required. Works concerning objective interpretation of ABO compatibility test have been reported but the proposed techniques cannot be easily translated to the patient's bedside. We propose a prototype device which demonstrates the easy use of biochip technology to perform this test: it contains a fluidic system, biochips (two to test the patient and two to test the red cell concentrates) and an optical absorbance detection module. When blood is applied to the biochips, red blood cells are trapped onto the surface if antigens and antibodies are complementary (positive chips). If they are not complementary, very little red blood cells are adsorbed (negative chips). Percentages of surface covered with red blood cells in negative biochips are 2% ± 2 (red cell concentrates) and 1% ± 1 (whole blood). This proves that the fluidic configuration leads to an optimum control of fluids flows with little retention of red blood cells in the circuitry. These percentages increase to 96% ± 3 and 82% ± 8 for red cell concentrates and whole blood respectively. This demonstrates a strong and specific immunocapture of red blood cells on positive chips. Furthermore, optical detection proves to be efficient at critical red blood cells concentrations (108 C/mL) and absorbance strongly correlates to the percentage of red blood cells captured by antibodies.

International audience; We present a simple optical micro-system used to measure the transmission spectra of oocytes in order to qualify their maturation stage. Two applications of the device are possible: (i) the evaluation of the maturation stages of oocytes, and (ii) the development of a fertilization indicator. For the first application, CV, MI and MII oocytes were also analysed. Transmission spectra allow the 3 maturation stages to be identified but cannot be used to estimate the maturity of an unknown oocyte. Oocytes are subject to continuous development. This is why spectral separation of the 3 maturation stages cannot be made although they can be visually identified. However, the visual observation remains biologist-dependent. We therefore investigated the temporal maturation evolution of the oocytes in terms of transmission spectra and probability analysis. Results show that oocytes to be fertilized should not only be chosen in the MII stage, but also at the right time during the MII stage. This particular aspect requires further investigation. However, spectral measurements could be used as a technique for monitoring the maturation evolution of the oocytes. Fertilized oocytes exhibiting fertilization abnormalities were also tested. The device proved to be an efficient fertilization indicator.

International audience; In vitro Fertilisation (IVF) is one of the therapeutic techniques offered to patients suffering from reproduction difficulties. Among the various steps involved in gamete manipulation, especially in intra cytoplasmic sperm injection (ICSI), the determination of the cell to be fertilised is critical. Usually, the choice of the oocyte relies on a visual checking of the maturity of the cell and on its morphological properties. Our current work deals with the fabrication of labs-on-chip (LOC), devoted to the characterisation of the cells before fertilisation. They consist of a platform that includes different analysis tools and a system that allows the accurate displacement between the different analysis bays. The first issue that must be addressed is the capture, the transportation and the trapping of a single oocyte on the LOC surface.We recently proposed a system based on micro-translators used for long distance transportation and micro-fluidics for accurate trapping. In this paper, we demonstrate a full micro-fluidic system which allows both, the long range displacement and the accurate trapping of a single oocyte. This simplifies the LOC because there is no more need for any micro-motor or complex mechanical systems.We also demonstrate the first optical sensor that quantifies the degree of maturity of the cell to be fertilised. This sensor can also be used as a fertilisation indicator.

Compensation techniques for producing well defined corner in KOH-etched (1 0 0) silicon have widely been proposed. However, the case of apertures connected with V-grooves has apparently not yet been published. In this paper, we present a compensation technique used in order to produce well defined square apertures connected with V-grooves. A full description of the KOH etching process, simulation methods as well as experimental confirmations are presented here. The technique is very easy to use and is convenient for any size of apertures and V-grooves. The structure obtained with this technique are of interest in many micro-machining domains, especially in the field of micro-fluidics and micro-biology.

International audience; ince rubella vaccine was established, cytomegalovirus infection has become the most frequent cause of congenital infections. The French Health Authority is urging a diagnosis at birth for newborns. Since no screening device is commercially available, a consortium has been established to set-up an original device. The project has been funded by the French National Research Agency. The device consists of a disposable cartridge containing the biological sample and the reactive liquids required for immuno-fluorescencence detection on a functionalized surface. It also consists of a mobile reader used to drive the fluids onto the biosensor and to ensure the optical measurement. Positive and negative samples can be discriminated with a fluorescence intensity ratio of 3.

A Mach–Zehnder unbalanced LiNbO3 integrated modulator with independent control of the phase of each arm is incorporated into the reference arm of a low coherence interferometer set-up. Using different RF modulation frequency and processing electronics tuned to these frequencies, the system can be used for simultaneous interrogation of the signal reflected from two different depths in tissue or from two different axial positions in profilometry. When a pair of XY scanning mirrors are incorporated into the sensing arm, then two en-face images from different axial positions can be simultaneously produced. The depth separation between the axial positions of the points or layers interrogated is equal to half of the modulator path difference. The operation of the system is illustrated by displaying simultaneously two images from a coin.

In this paper, we present a new keying structure which enhances the secrecy of an already relatively secure coherence modulation method we developed recently. The originality of the method consists in using an encrypting key composed of a large amplitude – low frequency part and a low amplitude – high frequency part. These two components ensure that the spectrum, as well as the signal tapped by an eavesdropper, are efficiently corrupted. When the key is applied simultaneously to both the encoder and the decoder, the signal is correctly restored. Both theoretical aspects and experimental confirmations are presented in this paper.