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The development of amphetamine-ion-selective microelectrodes using electrochemical polymerization and microfabrication technologies is reported in this study. The microelectrodes include polypyrrole films electrochemically polymerized and doped with cosane anion ([3,3′-Co(1,2-C2B9H11)2]−) as the internal solid contact layer between the polymeric sensitive membrane and platinum working microelectrode. Several poly(vinyl chloride)-type membranes with different compositions of plasticizers/ionophore were drop casted on the conducting polymer layer, polypyrrole[3,3′-Co(1,2-C2B9H11)2]. Potentiometric measurements were performed to calibrate the response of the developed chemical sensors. The sensor was highly sensitive to amphetamine using a membrane composition of 26 wt% poly (vinyl chloride), 63 wt% di-butyl phthalate, 6 wt% sodium tetraphenylborate, and 5 wt% dibenzo-18-crown 6-ether. A high and linear response was demonstrated within the concentration range from 10−5 to 10−3 M with a slope of 53 mV/decade and a limit of detection of 4 × 10−5 M. A Reilley diagram shows that the sensor signal is stable for a working pH between 1.50 and 8.50. The chemical sensor was highly selective to amphetamine when compared to other interfering ions and compounds including K+, Na+, , D,L-phenylalanine, caffeine, (±)-epinephrine bitartrate salt, and N-formylamphetamine using the fixed interference method with coefficients of selectivity (Log) from −1.40 to −1.15. [ABSTRACT FROM AUTHOR]

We report the development of a chemical sensor based on a Co(II) phthalocyanine acrylate polymer (Co(II)Pc-AP) for perchlorate anion detection. We have used two types of transducers, silicon nitride (Si3N4/ and hafnium oxide (HfO2/. The adhesion of the Co(II)Pc-AP on different transducers and their surface qualities have been studied by contact angle measurements. We have studied the pH effect on Al/Si/SiO2/HfO2/electrolyte capacitance values for different phosphate buffer solutions (PBS). This optimization step has allowed a sensitivity value of about 44mV decade-1 towards H+ ions. The fabricated sensors based on Si3N4 and HfO2 transducers functionalized with a Co(II)Pc-AP membrane have been characterized by C(V) measurements for different perchlorate concentrations (from 10-7 to 10-2 M). The sensor developed with the HfO2 transducer shows better performances compared to that based on Si3N4: a larger detection range (10-7 to 10-2 and 10-3 to 10-2 M, respectively) and lower detection limits (10-7 and 10-3 M). The specificities of our perchlorate sensor have been tested for some interfering ions (nitrate, sulfate and carbonate). [ABSTRACT FROM AUTHOR]

Abstract: In this work we present a biosensor based on olfactory receptors as a new bioelectronic device for detecting the presence and for measuring the concentration of specific odorants. To increase the surface of transducers, and consequently amplify the electrochemical signal, we generated gold nanoparticles on the surface of gold electrode. The characterization of the nanoparticles modified electrode surface allow to determine an increase of the surface area by a factor of 2.6 ±.0.4 (n = 4). Nanosomes from yeast containing olfactory receptor OR1740 with a cmyc tag were put in contact with the anti-cmyc antibody modified electrodes. Immobilization of nanosomes led to an increase in charge transfer resistance. This effect is amplified in the presence of gold nanoparticles by a factor of 3 ± 0.5. [Copyright &y& Elsevier]

In this study we extend our previous work that concerns structural test which is static test. So, in this paper we propose a verification method to test functional aspect of the data base and dynamic. Our work is based on UML diagrams and consists to explore these diagrams such sequence diagram and class diagram. The result is to generate a set of functional test in the objective to validate the function aspect of our method implemented in each class. In next stage the execution of the method permits us to verify dynamic aspect of classes." new object created. [ABSTRACT FROM AUTHOR]

In its ionic form, copper is a potentially toxic substance, thus, there is a need for developing a sensor to detect low levels of copper in environmental samples. A new capacitive biosensor sensitive to copper(II) was developed. This was achieved by the deposition of the new synthesized ionophore 4‐phenyl‐4‐sulfide‐11‐(1‐oxodecyl)‐1,7‐dithia‐11‐aza‐4‐phosphacyclotetradecane using the Langmuir‐Blodgett (LB) technique. The LB films formed on the Si 3 N 4 /SiO 2 /Si substrate were characterized using X‐ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and electrochemical impedance spectroscopy (EIS). The shift of the admittance curves owing to the variation of the Cu 2+ concentration shows that the device is sensitive to this ion. [ABSTRACT FROM AUTHOR]

Abstract: Planar all-solid-state hydrogen sensing microelectrodes have been constructed and investigated. A novel conductive polymer, polypyrrole (PPy) doped with cobaltabis(dicarbollide) ions ([3,3′-Co(1,2-C2B9H11)2]−), thin film was galvanostatically grown over a solid substrate (Pt) and acted as an internal solid contact layer between the solid surface (Pt) and the polymeric sensitive membrane. The potentiometric response characteristics of this new kind of microelectrode based on tri-n-dodecylamine (TDDA) ionophore were evaluated. They exhibited excellent selectivity for the primary ion and a linear response over the pH range 3.5–11.0 with a slope of 52±2 mV decade−1. The selectivity properties have been examined. The results obtained were comparable to that of a conventional ion-selective electrode (ISE) based on the same ionophore. [Copyright &y& Elsevier]