T. Shishkanova - Academia.edu (original) (raw)
Papers by T. Shishkanova
Analytica Chimica Acta, 2007
The ion selective electrode (ISE)-based potentiometric approach is shown to be an effective means... more The ion selective electrode (ISE)-based potentiometric approach is shown to be an effective means of characterizing the anion recognition sites in the molecular receptor calix[2]pyridino[2]pyrrole (CPP). In particular, potentiometric pH-measurements involving the use of experimental PVCmembranes based on CPP revealed the existence of both mono-and diprotonated forms of the receptor under readily accessible conditions. Based on these analyses, apparent surface protonation constants for this heterocalixarene were found to lie between 8.5-8.9 (pK B1) and 3.3-3.8 (pK B2). CPP was found to interact with targeted anionic analytes based on both coulombic and hydrogen bond interactions, as inferred from varying the kinds of ionic sites present within the membrane phase. Potentiometric selectivity studies revealed that CPP preferred "Y-shaped" anions (e.g. acetate, lactate, benzoate) over spherical anions (e.g. fluoride and chloride), fluoride over chloride within the set of spherical anions, and the ortho-isomer over the corresponding meta-and para-isomers in the case of hydroxybenzoate (salicylate and congeners). In the context of this study the advantages of potentiometric determinations of acetylsalicylic acid using optimized PVC-membranes based on CPP relative to more conventional PVC-membrane ISEs based on traditional anion exchanger were also demonstrated.
Electroanalysis, 2009
We report a novel way to improve the recognition of highly hydrated sulfate anions. It is shown t... more We report a novel way to improve the recognition of highly hydrated sulfate anions. It is shown that polyaniline (PANI) layer deposited on the poly(vinyl chloride) (PVC) membrane favors transport of highly hydrated anions due to stronger PANI hydration in their presence.
Gunshot residues occurring on a crime scene or on the body of the suspect are forensic clue for t... more Gunshot residues occurring on a crime scene or on the body of the suspect are forensic clue for the criminalists. With the growing demand of safety, there is a motivation to develop and introduce reliable and rapid sensing systems to detect gunshot residues. The sensing systems based on electrochemical principles possess a high sensitivity and specificity and are applicable in the alternative site testing (at a crime scene). This report summarizes the particular features of sampling and advantages of sensing of the gunshot residues using electrochemical methods. It is shown that the voltammetric sensors are attractive for the gunshot residue analysis. The success of voltammetric detection is connected with an introduction of new approaches in the field of sampling (particularly “swipe and scan”), new types of electrode materials and miniaturization.
Chem. Commun., 2016
We propose an innovative approach to detect a low molecular weight metabolite of neuroblastoma.
Analytical and Bioanalytical Chemistry - ANAL BIOANAL CHEM, 2003
Monomeric and polymeric 5-nitroquinoxaline derivatives disubstituted in the 2 and 3 positions wit... more Monomeric and polymeric 5-nitroquinoxaline derivatives disubstituted in the 2 and 3 positions with 2-pyrrolyl (A), 2-furyl (B) and 2-thienyl (C) groups were prepared and characterized. The substituted 5-nitroquinoxalines were used as active components in poly(vinyl chloride)-membrane and electropolymerized electrodes that were then tested as possible sensors for various cationic species. In contrast to the difurylnitroquinoxaline-based systems, the monomeric and polymeric dipyrrolyl- and dithienylquinoxaline electrodes displayed a good selectivity for Ag+ ions, providing a near-Nernstian response in the 10ч to 10ф mol Lу concentration range. The similar potentiometric behavior displayed by the monomeric and polymeric forms of systems A and C supports the contention that the main binding modes displayed by the monomeric forms are retained in the corresponding polymeric structures.
Biosensors and Bioelectronics, 2007
A novel application of a single stranded (ss) oligonucleotide as an active component of polymeric... more A novel application of a single stranded (ss) oligonucleotide as an active component of polymeric membrane in an ion-selective electrode (ISE) is described. The original oligonucleotides, oligo(dA)(15), modified by cholesterol, triphenylmethyl and hexadecyl derivatives, were immobilized into poly(vinyl chloride) (PVC) membrane using extraction protocol. In parallel, the adsorption protocol was used to immobilize unmodified oligo(dA)(15) on the PVC membrane based on tridodecylmethyammonium chloride (TDDMA(+)Cl(-)). Immobilization of ss oligonucleotide probe through spacer was more effective for the potentiometric detection of the hybridization between complementary oligonucleotides. It was found that cholesterol-oligo(dA)(15) modified membranes were sensitive toward complementary oligo(dT)(15) in the concentration range 2-80 nM at pH 7. An explanation for the detection mechanism is proposed.
Analytica Chimica Acta, 2008
Repeated depositions of polyaniline (PANI) have been used to control the thickness of the polymer... more Repeated depositions of polyaniline (PANI) have been used to control the thickness of the polymeric film deposited on poly(vinyl chloride) (PVC) membrane surface. The oxidation of aniline was carried out in a dispersion mode, i.e. in the presence of poly(N-vinylpyrrolidone) (PVP). Two kinds of PVC were used for this purpose: a non-plasticized PVC for the study of PANI deposition and PVC, plasticized with nitrophenyl octyl ether (NPOE), as a prototype of a liquid membrane electrode. The results of UV-visible and FTIR spectroscopies and electron microscopy showed that (1) the film thickness increased by about equal increments of approximately 40 nm after each polymerization, and (2) the interface with PVC was constituted by PANI film and adhering PANI-PVP colloidal particles. The various thicknesses of the deposited PANI films affected the potentiometric response of the NPOE/PVC membrane with and without an anion-exchanger. The potentiometric anionic response was observed with a minimal thickness of PANI film on the blank NPOE/PVC membrane. Sensitivity of the PANI film to pH occurred only with a blank NPOE/PVC membrane coated with a thick polymeric film, while it was strongly suppressed by the presence of a lipophilic anion-exchanger, tridodecylmethylammonium chloride (TDDMACl), in the membrane, regardless of the thickness of the polymer film. The thickness of the PANI film did not affect the anionic selectivity pattern of TDDMACl-based membranes to any great extent, but its presence improved and stabilized their potentiometric characteristics (sensitivity, linear-response range).
2012 37th International Conference on Infrared, Millimeter, and Terahertz Waves, 2012
An application of terahertz metamaterials as transducer elements for chemical sensors is reported... more An application of terahertz metamaterials as transducer elements for chemical sensors is reported. A planar array of split-ring resonators was formed from gold on the surface of silicon wafer and coated by polyaniline. Analyte binding to polyaniline leads to well measurable changes of the resonance frequency.
Proceedings of the National Academy of Sciences, 2002
The synthesis and characterization of two cytosine-substituted calix[4]pyrrole conjugates, bearin... more The synthesis and characterization of two cytosine-substituted calix[4]pyrrole conjugates, bearing the appended cytosine attached at either a beta- or meso-pyrrolic position, is described. These systems were tested as nucleotide-selective carriers and as active components of nucleotide-sensing ion-selective electrodes at pH 6.6. Studies of carrier selectivity were made using a Pressman-type model membrane system consisting of an initial pH 6.0 aqueous phase, an intervening dichloromethane barrier containing the calix[4]pyrrole conjugate, and a receiving basic aqueous phase. Good selectivity for the Watson-Crick complementary nucleotide, 5'-guanosine monophosphate (5'-GMP), was seen in the case of the meso-linked conjugate with the relative rates of through-membrane transport being 7.7:4.1:1 for 5'-GMP, 5'-AMP, and 5'-CMP, respectively. By contrast, the beta-substituted conjugate, while showing a selectivity for 5'-GMP that was enhanced relative to unsubstituted calix[4]pyrrole, was found to transport 5'-CMP roughly 4.5 times more quickly than 5'-GMP. Higher selectivities were also found for 5'-CMP when both the beta- and meso-substituted conjugates were incorporated into polyvinyl chloride membranes and tested as ion selective electrodes at pH 6.6, whereas near-equal selectivities were observed for 5'-CMP and 5'-GMP in the case of unsubstituted calix[4]pyrroles. These seemingly disparate results are consistent with a picture wherein the meso-substituted cytosine calix[4]pyrrole conjugate, but not its beta-linked congener, is capable of acting as a ditopic receptor, binding concurrently both the phosphate anion and nucleobase portions of 5'-GMP to the calixpyrrole core and cytosine "tails" of the molecule, respectively, with the effect of this binding being most apparent under the conditions of the transport experiments.
Electroanalysis, 2009
We report a novel way to improve the recognition of highly hydrated sulfate anions. It is shown t... more We report a novel way to improve the recognition of highly hydrated sulfate anions. It is shown that polyaniline (PANI) layer deposited on the poly(vinyl chloride) (PVC) membrane favors transport of highly hydrated anions due to stronger PANI hydration in their presence.
Analytica Chimica Acta, 2007
The ion selective electrode (ISE)-based potentiometric approach is shown to be an effective means... more The ion selective electrode (ISE)-based potentiometric approach is shown to be an effective means of characterizing the anion recognition sites in the molecular receptor calix[2]pyridino[2]pyrrole (CPP). In particular, potentiometric pH-measurements involving the use of experimental PVCmembranes based on CPP revealed the existence of both mono-and diprotonated forms of the receptor under readily accessible conditions. Based on these analyses, apparent surface protonation constants for this heterocalixarene were found to lie between 8.5-8.9 (pK B1) and 3.3-3.8 (pK B2). CPP was found to interact with targeted anionic analytes based on both coulombic and hydrogen bond interactions, as inferred from varying the kinds of ionic sites present within the membrane phase. Potentiometric selectivity studies revealed that CPP preferred "Y-shaped" anions (e.g. acetate, lactate, benzoate) over spherical anions (e.g. fluoride and chloride), fluoride over chloride within the set of spherical anions, and the ortho-isomer over the corresponding meta-and para-isomers in the case of hydroxybenzoate (salicylate and congeners). In the context of this study the advantages of potentiometric determinations of acetylsalicylic acid using optimized PVC-membranes based on CPP relative to more conventional PVC-membrane ISEs based on traditional anion exchanger were also demonstrated.
Electroanalysis, 2009
We report a novel way to improve the recognition of highly hydrated sulfate anions. It is shown t... more We report a novel way to improve the recognition of highly hydrated sulfate anions. It is shown that polyaniline (PANI) layer deposited on the poly(vinyl chloride) (PVC) membrane favors transport of highly hydrated anions due to stronger PANI hydration in their presence.
Gunshot residues occurring on a crime scene or on the body of the suspect are forensic clue for t... more Gunshot residues occurring on a crime scene or on the body of the suspect are forensic clue for the criminalists. With the growing demand of safety, there is a motivation to develop and introduce reliable and rapid sensing systems to detect gunshot residues. The sensing systems based on electrochemical principles possess a high sensitivity and specificity and are applicable in the alternative site testing (at a crime scene). This report summarizes the particular features of sampling and advantages of sensing of the gunshot residues using electrochemical methods. It is shown that the voltammetric sensors are attractive for the gunshot residue analysis. The success of voltammetric detection is connected with an introduction of new approaches in the field of sampling (particularly “swipe and scan”), new types of electrode materials and miniaturization.
Chem. Commun., 2016
We propose an innovative approach to detect a low molecular weight metabolite of neuroblastoma.
Analytical and Bioanalytical Chemistry - ANAL BIOANAL CHEM, 2003
Monomeric and polymeric 5-nitroquinoxaline derivatives disubstituted in the 2 and 3 positions wit... more Monomeric and polymeric 5-nitroquinoxaline derivatives disubstituted in the 2 and 3 positions with 2-pyrrolyl (A), 2-furyl (B) and 2-thienyl (C) groups were prepared and characterized. The substituted 5-nitroquinoxalines were used as active components in poly(vinyl chloride)-membrane and electropolymerized electrodes that were then tested as possible sensors for various cationic species. In contrast to the difurylnitroquinoxaline-based systems, the monomeric and polymeric dipyrrolyl- and dithienylquinoxaline electrodes displayed a good selectivity for Ag+ ions, providing a near-Nernstian response in the 10ч to 10ф mol Lу concentration range. The similar potentiometric behavior displayed by the monomeric and polymeric forms of systems A and C supports the contention that the main binding modes displayed by the monomeric forms are retained in the corresponding polymeric structures.
Biosensors and Bioelectronics, 2007
A novel application of a single stranded (ss) oligonucleotide as an active component of polymeric... more A novel application of a single stranded (ss) oligonucleotide as an active component of polymeric membrane in an ion-selective electrode (ISE) is described. The original oligonucleotides, oligo(dA)(15), modified by cholesterol, triphenylmethyl and hexadecyl derivatives, were immobilized into poly(vinyl chloride) (PVC) membrane using extraction protocol. In parallel, the adsorption protocol was used to immobilize unmodified oligo(dA)(15) on the PVC membrane based on tridodecylmethyammonium chloride (TDDMA(+)Cl(-)). Immobilization of ss oligonucleotide probe through spacer was more effective for the potentiometric detection of the hybridization between complementary oligonucleotides. It was found that cholesterol-oligo(dA)(15) modified membranes were sensitive toward complementary oligo(dT)(15) in the concentration range 2-80 nM at pH 7. An explanation for the detection mechanism is proposed.
Analytica Chimica Acta, 2008
Repeated depositions of polyaniline (PANI) have been used to control the thickness of the polymer... more Repeated depositions of polyaniline (PANI) have been used to control the thickness of the polymeric film deposited on poly(vinyl chloride) (PVC) membrane surface. The oxidation of aniline was carried out in a dispersion mode, i.e. in the presence of poly(N-vinylpyrrolidone) (PVP). Two kinds of PVC were used for this purpose: a non-plasticized PVC for the study of PANI deposition and PVC, plasticized with nitrophenyl octyl ether (NPOE), as a prototype of a liquid membrane electrode. The results of UV-visible and FTIR spectroscopies and electron microscopy showed that (1) the film thickness increased by about equal increments of approximately 40 nm after each polymerization, and (2) the interface with PVC was constituted by PANI film and adhering PANI-PVP colloidal particles. The various thicknesses of the deposited PANI films affected the potentiometric response of the NPOE/PVC membrane with and without an anion-exchanger. The potentiometric anionic response was observed with a minimal thickness of PANI film on the blank NPOE/PVC membrane. Sensitivity of the PANI film to pH occurred only with a blank NPOE/PVC membrane coated with a thick polymeric film, while it was strongly suppressed by the presence of a lipophilic anion-exchanger, tridodecylmethylammonium chloride (TDDMACl), in the membrane, regardless of the thickness of the polymer film. The thickness of the PANI film did not affect the anionic selectivity pattern of TDDMACl-based membranes to any great extent, but its presence improved and stabilized their potentiometric characteristics (sensitivity, linear-response range).
2012 37th International Conference on Infrared, Millimeter, and Terahertz Waves, 2012
An application of terahertz metamaterials as transducer elements for chemical sensors is reported... more An application of terahertz metamaterials as transducer elements for chemical sensors is reported. A planar array of split-ring resonators was formed from gold on the surface of silicon wafer and coated by polyaniline. Analyte binding to polyaniline leads to well measurable changes of the resonance frequency.
Proceedings of the National Academy of Sciences, 2002
The synthesis and characterization of two cytosine-substituted calix[4]pyrrole conjugates, bearin... more The synthesis and characterization of two cytosine-substituted calix[4]pyrrole conjugates, bearing the appended cytosine attached at either a beta- or meso-pyrrolic position, is described. These systems were tested as nucleotide-selective carriers and as active components of nucleotide-sensing ion-selective electrodes at pH 6.6. Studies of carrier selectivity were made using a Pressman-type model membrane system consisting of an initial pH 6.0 aqueous phase, an intervening dichloromethane barrier containing the calix[4]pyrrole conjugate, and a receiving basic aqueous phase. Good selectivity for the Watson-Crick complementary nucleotide, 5'-guanosine monophosphate (5'-GMP), was seen in the case of the meso-linked conjugate with the relative rates of through-membrane transport being 7.7:4.1:1 for 5'-GMP, 5'-AMP, and 5'-CMP, respectively. By contrast, the beta-substituted conjugate, while showing a selectivity for 5'-GMP that was enhanced relative to unsubstituted calix[4]pyrrole, was found to transport 5'-CMP roughly 4.5 times more quickly than 5'-GMP. Higher selectivities were also found for 5'-CMP when both the beta- and meso-substituted conjugates were incorporated into polyvinyl chloride membranes and tested as ion selective electrodes at pH 6.6, whereas near-equal selectivities were observed for 5'-CMP and 5'-GMP in the case of unsubstituted calix[4]pyrroles. These seemingly disparate results are consistent with a picture wherein the meso-substituted cytosine calix[4]pyrrole conjugate, but not its beta-linked congener, is capable of acting as a ditopic receptor, binding concurrently both the phosphate anion and nucleobase portions of 5'-GMP to the calixpyrrole core and cytosine "tails" of the molecule, respectively, with the effect of this binding being most apparent under the conditions of the transport experiments.
Electroanalysis, 2009
We report a novel way to improve the recognition of highly hydrated sulfate anions. It is shown t... more We report a novel way to improve the recognition of highly hydrated sulfate anions. It is shown that polyaniline (PANI) layer deposited on the poly(vinyl chloride) (PVC) membrane favors transport of highly hydrated anions due to stronger PANI hydration in their presence.