Ion-sensitive field-effect transistors fabricated in a commercial CMOS technology’,

Abstract: The fabrication of pH-sensitive ISFET devices in an unmodified two-metal commercial CMOS technology (1.0 m from Atmel-ES2) is reported. The ISFET devices have a gate structure compatible with the CMOS process, with an electrically floating electrode consisting on polysilicon plus the two metals. The passivation oxynitride layer acts as the pH-sensitive material in contact with the liquid solution. The devices have shown good operating characteristics, with a 47 mV/pH response. The use of a commercial CMOS process allows the straightforward integration of signal-processing circuitry. An ISFET amplifier circuit has been integrated with the ISFET sensors

Ion-sensitive field-effect transistors fabricated in a commercial CMOS technology

The fabrication of pH-sensitive ISFET devices in an unmodified two-metal commercial CMOS technology (1.0 um from Atmel-ES2) is reported. The ISFET devices have a gate structure compatible with the CMOS process, with an electrically floating electrode consisting on polysilicon plus the two metals. The passivation oxynitride layer acts as the pH-sensitive material in contact with the liquid solution. The devices have shown good operating characteristics, with a 47 mV/pH response. The use of a commercial CMOS process allows the straightforward integration of signal-processing circuitry. An ISFET amplifier circuit has been integrated with the ISFET sensors.Peer reviewe

A Highly Sensitive Potentiometric Amphetamine Microsensor Based on All-Solid-State Membrane Using a New Ion-Par Complex, [3,3′-Co(1,2-closo-C2B9H11)2]− C9H13NH+

In the present work a highly sensitive ion-selective microelectrode for the detection of amphetamine is presented. For this purpose, a novel ion-par complex based on the metallocarborane, cobalt bis(dicarbollide) anion ([3,3′-Co(1,2-C2B9H11)2]−) coupled to amphetamonium cation has been prepared as the active site for amphetamine recognition. The prepared ion-par complex was incorporated to a PVC-type sensitive membrane. It was then drop-casted on the top of a gold microelectrode previously modified with a solid contact layer of polypyrrole. This novel amphetamine microsensor has provided excellent and quick response within the range 10−5 M to 10−3 M of amphetamine concentration, a limit of detection of 12 µM and a slope of 60.1 mV/decade. It was also found to be highly selective toward some potential interference compounds when compared to amphetamine.The authors acknowledge the financial support from the European Union’s Horizon 2020 research and innovation programme entitled MicroMole and HEARTEN grant agreement No. 653626 and No. 643694 respectivel

Multiplexed Frequency Spectrum Analyzer Instrumentation for the Characterization of Multiple QCM-Based Biosensors

In this contribution, we present novel multiplexed frequency spectrum analyzer instrumentation to extract operational parameters and completely characterize the frequency response of an array of quartz_crystal microbalance sensors. The effectiveness of the proposed instrumentation is proven by experimental measurements over a range of frequencies. © 2007 IEEE

A Fully Integrated Electrochemical BioMEMS Fabrication Process for Cytokine Detection: Application for Heart Failure

AbstractIn this present study, a fully integrated BioMEMS was developed using silicon technology to simultaneously detect varying cytokine biomarkers: interleukin-1 (IL-1), interleukin-10 (IL-10), and interleukin-6 (IL-6) using eight gold working microelectrodes (WE). The biomarkers are one of many antigens that are secreted in acute stages of inflammation after left ventricle assisted device (LVAD) implantation for patients suffering from heart failure (HF). The monoclonal antibodies (mAb): anti-human IL-1, IL-10, and IL-6 were immobilized onto gold microelectrodes through functionalization with carboxyl diazonium, respectively. Cyclic voltammetry (CV) was applied during the microelectrode functionalization process to characterize the gold microelectrode surface properties, while electrochemical impedance spectroscopy (EIS) was used to characterize the modified gold microelectrodes. The BioMEMS was highly sensitive towards the three cytokines in a range of 1 pg/mL to 15 pg/mL, which is the window where acute inflammations were observed

Directional alignment of MG63 cells on polymer surfaces containing point microstructures

MG63 cells cultured on regular arrays of point microstructures (posts and holes) are shown to preferentially align at certain angles to the pattern of the structures, at 08, 308, and 458 in particular. The effect is found to be more pronounced for post rather than hole structures(although no significant difference is found for the angles the cells make to the holes or posts) and is thought to be due to the fact that the cells use the posts as anchorage points to hold themselves to the surface. It is also shown that cells preferentially align with the structures depending on the dimensions of the structures and the distance between neighboring structures. This is important when designing structured surfaces for cell–surface interaction studies for materials to be used in, for example, drug delivery or tissue engineering.Postprint (published version

Electrochemical Boron-Doped Diamond Film Microcells Micromachined with Femtosecond Laser: Application to the Determination of Water Framework Directive Metals

Planar electrochemical microcells were micromachined in a microcrystalline boron-doped diamond (BDD) thin layer using a femtosecond laser (Photo 1). The electrochemical performances of the new laser-machined BDD microcell were assessed by differential pulse anodic stripping voltammetry (DPASV) determinations, at nM level, of the four heavy metal ions of the European Water Framework Directive (WFD): Cd(II), Ni(II), Pb(II), Hg(II). The results are compared with those of previously published BDD electrodes [1]. The calculated detection limits are 0.4 nM, 6.8 nM and 5.5 nm 2.3 nM, and the linearities go up to 35nM, 97nM, 48nM and 5nM for respectively Cd(II), Ni(II) Pb(II) and Hg(II). The detection limits meet with the environmental quality standard of the WFD for three of the four metals. It was shown that the four heavy metals could be detected simultaneously, in the concentration ratio usually measured in sewage or runoff waters