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A novel iodide ion-selective electrode has been produced based on a molecular deposition technique in which water-soluble porphyrin was alternatively deposited with water-soluble polypyrrole on a 2-aminoethanethiol modified silver electrode. The potentiometric response is independent of pH of the solution between pH 1 and 7, while it is dependent on the nature of the medium. The electrode has a linear...
A flow injection potentiometric method for the rapid determination of paraquat in herbicide formulations and biological samples is described. It is based on the utilization of a flow-through potentiometric detector containing polyvinyl chloride-immobilised octamethylcyclotetrasiloxane, a lipophilic plasticizer (tetra-n-undecyl 3,3′,4,4′-benzophenone tetracarboxylate) and membrane additive potassium...
This paper presents a development of a solid support RT phosphorescence procedure for the determination of polycyclic aromatic hydrocarbons, based on the use of a Xenon flash lamp as the excitation source, a fiber optic sensor as a guide of light, an imaging spectrograph and a cooled two dimensional charge coupled device as the detector. Non fluorescent Whatman N o 1 filter paper was used...
A simultaneous detection sequential injection analysis (SIA) system is proposed for the determination of S and R captopril using a potentiometric, enantioselective membrane electrode based on maltodextrin (DE=14-17) for the assay of S-captopril and an amperometric biosensor for the assay of R-captopril. The proposed SIA system can be utilized reliably for the on-line simultaneous detection of the...
A PVC membrane based on bis-pyridine tetramide macrocycle exhibits a good response for silver ion over a wide concentration range (1.0x10 -1 -4.0x10 -5 mol l -1 ). The electrode has a relatively fast response time and can be used for more than 5 months without observing any divergence. High selectivity for Ag + ions over that of Na + , K +...
Potential response of cadmium(II) ion selective electrode based on cyanocopolymer matrices and 8-hydroxyquinoline as ionophore has been evaluated by varying the amount of ionophore, plasticizer and the molecular weight of the cyanocopolymer. The sensitivity, working range, response time, and metal ions interference have shown a significant dependence on the concentration of ionophore, plasticizer...
A novel chemiluminescence (CL) sensor for isoniazid combined with flow-injection technology is presented in this paper. The analytical reagents, luminol and ferricyanide, were both immobilized on an anion-exchange column. The CL signal produced by the reaction between luminol and ferricyanide, which were eluted from the column through sodium phosphate injection, was decreased in the presence of isoniazid...
Whole-cell luminescent bioreporter sensors based on immobilized recombinant Escherichia coli are described and evaluated. The sensors were prepared by glutaraldehyde-anchoring of nonspecific anti-E. coli antibodies on aminosylilated gold or silica glass surfaces with subsequent attachment of the probe bacteria. We demonstrate the generality of the concept by attachment of several E. coli strains that...
Mesostructured tin oxide with high specific surface area was synthesized using cationic surfactant (cetyltrimethylammonium bromide, CTAB: CH 3 (CH 2 ) 15 N + (CH 3 ) 3 Br - ) as the organic template and hydrous tin chloride (SnCl 4 .5H 2 O) and NH 4 OH as the inorganic precursors under acidic conditions at ambient...
The potentiometric response characteristics of cesium ion selective PVC membrane electrode employing calix[4]crown ether-ester as an ionophore were investigated. The electrode exhibit a good response for cesium ion over wide concentration range of 5.0x10 -6 -1.0x10 -1 M with a Nernstian slope of 59 mV per decade. The detection limit of electrode is 5.0x10 -6 ...
A new ion-selective PVC membrane electrode based on salicylaldehyde thiosemicarbazone as an ionophore is developed successfully as sensor for mercury(II) ions. The electrode shows excellent potentiometric response characteristics and displays a linear log[Hg 2+ ] versus EMF response over a wide concentration range of 1.778x10 -6 -1.0x10 -1 M with Nernstian slope...
A chemiluminescence (CL) biosensor on a chip coupled to microfluidic system is described in this paper. The CL biosensor measured 25x45x5 mm in dimension, was readily produced in analytical laboratory. Glucose oxidase (GOD) was immobilized onto controlled-pore glass (CPG) via glutaraldehyde activation and packed into a reservoir. The analytical reagents, including luminol and ferricyanide, were electrostatically...
A novel Raman sensor using a liquid-core optical waveguide is reported, implementing a Teflon-AF 2400 tube filled with water. An aqueous analyte mixture of benzene, toluene and p-xylene was introduced using a 1000 μl sample loop to the liquid-core waveguide (LCW) sensor and the analytes were preconcentrated on the inside surface of the waveguide tubing. The analytes were then eluted from the waveguide...
Four ionophores containing bipyridyl groups on a 7-deoxycholic amide derivative scaffold were designed and synthesized. Potentiometric evaluation of the Poly(vinyl chloride) (PVC) membranes containing those deoxycholic amides bearing bipyridyl moieties with a short linkage showed good affinity to silver(I) ion over alkali, alkaline earth and other transition metal cations. However, two bipyridyl groups...
A new type of solid polymer electrolyte (SPE) PH 3 electrochemical sensor is reported. The oxidation of PH 3 on the SPE-Pt electrode is studied by electrochemical and XPS methods. At the same time, the linearity, the stability and response time of the sensor is investigated and discussed. The results obtained indicate the SPE-based PH 3 sensor possesses a number of attractive...
The potentiometric response characteristics of electrodes based on organic trialkyl/aryl-tin compounds combined with various amounts of anionic additive (NaTFPB) were investigated in 0.1M bis-Tris-H 2 SO 4 buffer solution at pH 7.0. The best result for phosphate sensing was obtained for the electrode membrane containing tributyltin chloride and 25mol% NaTFPB, where the electrode exhibits...
The possibility of applying natural monocrystaline pyrite as a sensor for the potentiometric titration of weak acids in N,N-dimethylformamide, methylpyrrolidone and pyridine was investigated. The potential of this electrode in N,N-dimethylformamide, methylpyrrolidone and pyridine exhibits a sub-Nernst dependence. In N,N-dimethylformamide the slope (mV/pH) is 39.0 and in methylpyrrolidone it is 45...
This paper introduces a mathematical model which makes it possible both to determine the concentration of photosynthetic herbicides and to obtain a quantitative parameter in order to compare their activity using a previously described sensing system. The working principle involves the changes in absorption properties at 860nm of the reaction centre (RC) isolated from the bacteria Rhodobacter sphaeroides...
Two gold-thiolate monolayer-protected nanoparticles were synthesized and used as interfacial layers on chemiresistor sensors for the analysis of violate organic compounds (VOCs). Toluene, ethanol, acetone and ethyl acetate were chosen as the target vapors. Both the resistance and capacitance were measured as the function of analyte concentrations. The effect of humidity on the sensor sensitivity to...
Tweezer-type and non-tweezer-type ionophores containing dithiocarbamoyl groups on a 7-deoxycholic amide or cholane derivatives were designed and synthesized. Potentiometric evaluation of the poly(vinyl chloride) (PVC) membranes containing those deoxycholic amides/cholanes linked with tweezer-type dithiocarbamoyl moieties showed excellent affinity and selectivity to silver(I) ion over alkali, alkaline...
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