Publications

2007
R. Okner, Oron, M. , Tal, N. , Mandler, D, and Domb, A. J. 2007. Electrocoating Of Stainless Steel Coronary Stents For Extended Release Of Paclitaxel.. Mater. Sci. Eng., Cmaterials Science & Engineering, C: Biomimetic And Supramolecular Systems, 27, Pp. 510 - 513. Abstract
The purpose of this study was to examine chem., mech. and Paclitaxel release properties of the new coating onto the stainless steel coronary stents. Stainless steel coronary stents were coated with elec. polymerizable pyrrole deriv., applying cyclic voltammetry technique in a simple 3 electrode cell, while stent represented a working electrode. Resulted polymer coating were examd. by cyclic voltammetry (elec. parameters), SEM (morphol. images), goniometer (hydrophobisity of the surface), profilometer ( thickness of the polymer coating). Polymer stability was examd. by placing the coated stent into 1:1 soln. of fetal calf serum:seline soln. up to 1 yr and under the mouse skin for 1 wk. Paclitaxel loading were carried out by immersion into drug soln. and its release was detected by HPLC. Reproducible one step method for coating different pyrrole derivs. on stainless steel coronary stents provided thin (single micrometers), uniform coating with various morphol. and hydrophobisity. These surface properties allow to load appropriate amt. of Paclitaxel and to release it slowly up to a month. [on SciFinder(R)]
Galit Shustak, Shaulov, Yulia , Domb, Abraham J. , and Mandler, Daniel . 2007. Electrostatic Attachment Of Gold And Poly(Lactic Acid) Nanoparticles Onto Omega-Aminoalkanoic Acid Self-Assembled Monolayers On 316L Stainless Steel. Chemistrychemistry (Weinheim An Der Bergstrasse, Germany), 13, Pp. 6402 - 7. Abstract
The assembly of poly(lactic acid) (PLA) nanoparticles on a 12-aminodecanoic acid (ADA) self-assembled monolayer (SAM) is described. Assembly is accomplished through electrostatic interactions between the positively charged SAM and the negatively charged PLA nanoparticles. The strategy used involves two steps in which a preliminary electrochemical coating of the ADA SAM is followed by a second step that involves immersing the SAM in a solution containing gold or PLA nanoparticles. The SAM was characterized by using cyclic voltammetry (CV), X-ray photoelectron spectroscopy (XPS), FTIR spectroscopy, and contact angle measurements, whereas scanning electron microscopy (SEM) was used to image the nanoparticles after electrostatic attachment was achieved. We found that the surface coverage of the nanoparticles could be controlled by modulating the electrostatic interactions between the negatively charged particles and the positively charged SAM surface by varying the pH of the nanoparticle solution, the immersion time, and the number of cyclic voltammetry scans under which the SAM was formed.[on SciFinder (R)]
Galit Shustak, Shaulov, Yulia , Domb, Abraham J. , and Mandler, Daniel. . 2007. Electrostatic Attachment Of Gold And Poly(Lactic Acid) Nanoparticles Onto Ω-Aminoalkanoic Acid Self-Assembled Monolayers On 316L Stainless Steel.. Chem. - Eur. J.chemistry - A European Journal, 13, Pp. 6402 - 6407. Abstract
The assembly of poly(lactic acid) (PLA) nanoparticles on a 12-aminodecanoic acid (ADA) self-assembled monolayer (SAM) is described. Assembly is accomplished through electrostatic interactions between the pos. charged SAM and the neg. charged PLA nanoparticles. The strategy used involves 2 steps in which a preliminary electrochem. coating of the ADA SAM is followed by a second step that involves immersing the SAM in a soln. contg. gold or PLA nanoparticles. The SAM was characterized by cyclic voltammetry (CV), XPS, FTIR spectroscopy, and contact angle measurements, whereas SEM was used to image the nanoparticles after electrostatic attachment was achieved. The authors found that the surface coverage of the nanoparticles could be controlled by modulating the electrostatic interactions between the neg. charged particles and the pos. charged SAM surface by varying the pH of the nanoparticle soln., the immersion time, and the no. of cyclic voltammetry scans under which the SAM was formed. [on SciFinder(R)]
Leora Shapiro and Mandler, Daniel. . 2007. Formation Of A Molecular Glue Based On The Electrochemical Reduction Of 4-Hydroxyphenyldiazonium For The Attachment Of Thin Sol-Gel Film On Glassy Carbon.. Z. Phys. Chem. (Muenchen, Ger.)Zeitschrift Fuer Physikalische Chemie (Muenchen, Germany), 221, Pp. 1237 - 1243. Abstract
The covalent attachment of a sol-gel thin film onto a glassy carbon electrode was accomplished through the electrochem. redn. of 4-hydroxyphenyldiazonium. The latter forms a very thin layer on the glassy carbon with hydroxyl groups, through which the sol-gel is attached. This mol. glue improves the adhesion of thin layers of sol-gel to a carbonaceous surface. [on SciFinder(R)]
Galit Shustak, Gadzinowski, Mariusz , Slomkowski, Stanislaw , Domb, Abraham J. , and Mandler, Daniel. . 2007. A Novel Electrochemically Synthesized Biodegradable Thin Film Of Polypyrrole-Polyethylene Glycol-Polylactic Acid Nanoparticles.. New J. Chem.new Journal Of Chemistry, 31, Pp. 163 - 168. Abstract
Nanoparticles having reactive pyrrole residues were prepd. from poly(1-ethoxyethyl glycidyl ether)-block-poly(L,L-lactide) block copolymer. The nanoparticles were electropolymd. in aq. media through the oxidn. of the pyrrole residue and in the presence of pyrrole to form a nanocomposite thin film. The novel synthesis of these pyrrole-functionalized nanoparticles is described and the electrochem. deposition of the corresponding coating is characterized using electrochem., SEM and EDX. [on SciFinder(R)]
Leora Shapiro, Marx, Sharon , and Mandler, Daniel. . 2007. Preparation And Characterization Of Ultra-Thin Sol-Gel Films.. Thin Solid Filmsthin Solid Films, 515, Pp. 4624 - 4628. Abstract
The formation and characterization of nanometer thick sol-gel films are reported. The films were prepd. by spin-coating of a dild. soln. of a silane precursor on a no. of different substrates. The effect of diln., rotation speed and nature of substrate on the thickness and homogeneity of the films was examd. Characterization of the films was carried out by profilometry, reflectance spectroscopy, at. force microscopy, adhesion test and electrochem. We find that the diln. factor has a pronounced effect on the film thickness. Moreover, the time of diln., namely, whether diln. was carried out before or after a period of hydrolysis, has a noticeable effect on the thickness as well as on the permeability of embedded species. [on SciFinder(R)]
Meirav Cohen-Atiya, Vadgama, Pankaj , and Mandler, Daniel. . 2007. Preparation, Characterization And Applications Of Ultrathin Cellulose Acetate Langmuir-Blodgett Films.. Soft Mattersoft Matter, 3, Pp. 1053 - 1063. Abstract
The prepn. and characterization of mono- and multilayers of cellulose acetate (CA) Langmuir-Blodgett films on indium tin oxide and gold surfaces were studied in detail for the first time. These layers were characterized by their thickness, wettability, morphol. and structure using various surface techniques. The thickness of a monolayer of CA based on XPS measurement was one nanometer. Multilayers of CA Langmuir films were homogeneously transferred onto solid surfaces. The permeation of different mols. across these films was studied using electrochem. in various redox solns. Our findings suggest that a membrane like structure is formed, which is less permeable as the no. of layers increases. Finally, potential applications of these ultrathin films as supports for accommodating biomols. or metal nanoparticles are presented. [on SciFinder(R)]
Marisa Sheffer, Vivier, Vincent , and Mandler, Daniel. . 2007. Self-Assembled Monolayers On Au Microelectrodes.. Electrochem. Commun.electrochemistry Communications, 9, Pp. 2827 - 2832. Abstract
Long chain alkanethiols self-assembled monolayers (SAMs) formed on Au microelectrodes showed higher sensitivity towards defects than the same monolayers on macroelectrodes. The anal. of cyclic voltammetry and electrochem. impedance spectroscopy (EIS) expts. performed on covered microelectrodes were consistent with the formation of pinholes of about 10 nm in diam. Moreover, the EIS data exhibited a specific behavior that was interpreted invoking the short circuiting of the pinholes impedance by the surrounding surface of the microelectrode in the high frequency domain, whereas in the low frequencies, the surface covered by the SAM was assume to act as an insulator. [on SciFinder(R)]
Giovanni Palmisano, Mandler, Daniel , Ciriminna, Rosaria , and Pagliaro, Mario. . 2007. Structural Insight On Organosilica Electrodes For Waste-Free Alcohol Oxidations.. Catal. Lett.catalysis Letters, 114, Pp. 55 - 58. Abstract
Org. modification of sol-gel catalytic glassy electrodes made of a thin layer of organosilica doped with nitroxyl radical TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy) crucially enhances stability in the waste-free oxidn. of alcs. to carbonyls in H2O. Structural comparison between analogous films made of organosilica and unmodified SiO2 shows that the origin of the pronounced stable activity of the ORMOSIL film lies in high hydrophobic and also in the pronounced low degree of hydrophilicity. [on SciFinder(R)]
2006
Meirav Cohen-Atiya, Nelson, Andrew , and Mandler, Daniel. . 2006. Characterization Of N-Alkanethiol Self-Assembled Monolayers On Mercury By Impedance Spectroscopy And Potentiometric Measurements.. J. Electroanal. Chem.journal Of Electroanalytical Chemistry, 593, Pp. 227 - 240. Abstract
Long chain n-alkanethiol self-assembled monolayers (SAMs) on a hanging Hg drop electrode were studied in detail for the 1st time by impedance spectroscopy (IS) and potentiometry. IS reveals the detailed behavior of the monolayers in the absence and presence of 2 1-electron redox couple: hexaammineruthenium(III) (Ru(NH3)63+) and tris(2,2’-bipyridine)cobalt(III) (Co(bpy)33+). The pinholes-free layers behave as almost ideal capacitors and are permeable to some extent to redox species, depending on their hydrophobicity. Co(bpy)33+ that exhibits sluggish kinetics on a bare Hg electrode reveals a more facile kinetics than Ru(NH3)63+ on an n-octadecanethiol/Hg interface. Potentiometric measurements recorded upon immersing the bare and SAM modified Hg electrode into a soln. contg. a mixt. of the oxidized and reduced forms of the redox couples provide invaluable information on the charge transfer across the monolayer and its ohmic resistance. While Ru(NH3)63+ cannot freely penetrate into the monolayer and therefore establishes a p.d. across the monolayer; penetration of Co(bpy)32+ into the film causes the Fermi level of the Hg surface to attain the Nernst potential of the soln. Finally, increasing the length of the alkane chain of the thiols increases linearly the ohmic resistance of the layer. [on SciFinder(R)]
Shlomit Kraus and Mandler, Daniel . 2006. Complexation Of Ferrous And Cupric Ions By Phenanthroline And Terpyridine Langmuir Films. Langmuirlangmuir : The Acs Journal Of Surfaces And Colloids, 22, Pp. 7462 - 4. Abstract
The complexation of Fe(II) and Cu(II) ions by phenanthroline and terpyridine-based Langmuir films was studied by the effect the added ions in the subphase on the isotherms. We found that Cu(II) had a pronounced effect on the isotherm consisting of phenanthroline moieties forming a square-planar 1:2 (Cu(II)/phenanthroline) complex. However, Fe(II) affected the isotherm made of 1:1 phenanthroline/terpyridine amphiphiles as a result of forming a pentacoordinate complex.[on SciFinder (R)]
Shlomit Kraus and Mandler, Daniel. . 2006. Complexation Of Ferrous And Cupric Ions By Phenanthroline And Terpyridine Langmuir Films.. Langmuirlangmuir, 22, Pp. 7462 - 7464. Abstract
The complexation of FeII and CuII ions by phenanthroline and terpyridine-based Langmuir films was studied by the effect the added ions in the subphase on the isotherms. We found that CuII had a pronounced effect on the isotherm consisting of phenanthroline moieties forming a square-planar 1:2 (CuII/phenanthroline) complex. However, FeII affected the isotherm made of 1:1 phenanthroline/terpyridine amphiphiles as a result of forming a pentacoordinate complex. [on SciFinder(R)]
Doron Burshtain and Mandler, Daniel . 2006. The Effect Of Surface Attachment On Ligand Binding: Studying The Association Of Mg2+, Ca2+ And Sr2+ By 1-Thioglycerol And 1,4-Dithiothreitol Monolayers. Phys Chem Chem Physphysical Chemistry Chemical Physics : Pccp, 8, Pp. 158 - 64. Abstract
The difference in the heterogeneous binding of Mg(2+), Ca(2+) and Sr(2+) ions by 1-thioglycerol (TG) and 1,4-dithiothreitol (DTT) spontaneously adsorbed monolayers on Au has been studied following the changes in the double layer capacity. A mathematical treatment, based on calculating the electrochemical potential difference at the monolayer-electrolyte interface, has followed our recent work which dealt with the acid-base equilibrium at the interface as a means of calculating the pK of ionizable SAMs and their binding with Cd(2+). Experimentally, spontaneously adsorbed monolayers of TG and DTT were assembled on Au surfaces and studied by impedance spectroscopy and alternating current voltammetry (ACV). The capacity was measured for each of the modified surfaces at increasing concentrations of the divalent metal ions separately. The goal of this study has been to examine the effect of metal ion binding by similar ligands that are differently attached onto the surface. TG and DTT monolayers differ in their flexibility, which is a result of their attachment to the surface through one and two arms, respectively. The general trend of the apparent heterogeneous association constants of the divalent metal ions, which were calculated from the capacity measurements, was substantially different from the classical Irving-Williams series that is applicable to homogeneous systems. This difference could be nicely explained by the reduction of the degree of freedom and flexibility of the attached ligands.[on SciFinder (R)]
Doron Burshtain and Mandler, Daniel. . 2006. The Effect Of Surface Attachment On Ligand Binding: Studying The Association Of Mg2+, Ca2+ And Sr2+ By 1-Thioglycerol And 1,4-Dithiothreitol Monolayers.. Phys. Chem. Chem. Phys.physical Chemistry Chemical Physics, 8, Pp. 158 - 164. Abstract
The difference in the heterogeneous binding of Mg2+, Ca2+ and Sr2+ ions by 1-thioglycerol (TG) and 1,4-dithiothreitol (DTT) spontaneously adsorbed monolayers on Au has been studied following the changes in the double layer capacity. A math. treatment, based on calcg. the electrochem. p.d. at the monolayer-electrolyte interface, has followed our recent work1 which dealt with the acid-base equil. at the interface as a means of calcg. the pK of ionizable SAMs and their binding with Cd2+. Exptl., spontaneously adsorbed monolayers of TG and DTT were assembled on Au surfaces and studied by impedance spectroscopy and a.c. voltammetry (ACV). The capacity was measured for each of the modified surfaces at increasing concns. of the divalent metal ions sep. The goal of this study has been to examine the effect of metal ion binding by similar ligands that are differently attached onto the surface. TG and DTT monolayers differ in their flexibility, which is a result of their attachment to the surface through one and two arms, resp. The general trend of the apparent heterogeneous assocn. consts. of the divalent metal ions, which were calcd. from the capacity measurements, was substantially different from the classical Irving-Williams series2-4 that is applicable to homogeneous systems. This difference could be nicely explained by the redn. of the degree of freedom and flexibility of the attached ligands. [on SciFinder(R)]
Abraham J. Domb, Mandler, Daniel , Danziger, Ishaiahu , Orom, Miriam , Okner, Regina , Shustak, Galit , Swed, Avi , and Tal, Noam. . 2006. Modified Conductive Surfaces Having Active Substances Attached Thereto And Uses Thereof.. Abstract
Novel processes for coating metal surfaces and/or for attaching active substances to metal surfaces, objects having coated metal surfaces and/or active substances attached thereto and uses thereof in the prepn. of implantable devices are disclosed. Thus, cyclic voltammetry of a stainless steel electrode in an acetonitrile soln. contg. 0.1 mM decanoic acid was performed to give a self-assembled monolayer on the electrode, showing advancing contact angle 59° and receding contact angle 45°. [on SciFinder(R)]
Galit Shustak, Domb, Abraham J. , and Mandler, Daniel . 2006. N-Alkanoic Acid Monolayers On 316L Stainless Steel Promote The Adhesion Of Electropolymerized Polypyrrole Films. Langmuirlangmuir : The Acs Journal Of Surfaces And Colloids, 22, Pp. 5237 - 40. Abstract
The formation of a self-assembled monolayer significantly promotes the adhesion of electrodeposited polypyrrole on stainless steel. The monolayer affects the nucleation and growth mechanism of polypyrrole as a result of its hydrophobic nature. This was confirmed by analyzing current-time transients of the initial stages of electropolymerization and was in agreement with AFM images.[on SciFinder (R)]
Galit Shustak, Domb, Abraham J. , and Mandler, Daniel. . 2006. N-Alkanoic Acid Monolayers On 316L Stainless Steel Promote The Adhesion Of Electropolymerized Polypyrrole Films.. Langmuirlangmuir, 22, Pp. 5237 - 5240. Abstract
The formation of a self-assembled monolayer significantly promotes the adhesion of electrodeposited polypyrrole on stainless steel. The monolayer affects the nucleation and growth mechanism of polypyrrole of its hydrophobic nature. This was confirmed by analyzing current-time transients of the initial stages of electropolymn. and was in agreement with AFM images. [on SciFinder(R)]
Meirav Cohen-Atiya and Mandler, Daniel . 2006. Studying Electron Transfer Through Alkanethiol Self-Assembled Monolayers On A Hanging Mercury Drop Electrode Using Potentiometric Measurements. Phys Chem Chem Physphysical Chemistry Chemical Physics : Pccp, 8, Pp. 4405 - 9. Abstract
A new approach based on measuring the change of the open-circuit potential (OCP) of a hanging mercury drop electrode (HMDE), modified with alkanethiols of different chain length conducted in a solution containing a mixture of Ru(NH3)6(2+) and Ru(NH3)6(3+) is used for studying electron transfer across the monolayer. Following the time dependence of the OCP allowed the extraction of the kinetic parameters, such as the charge transfer resistance (R(ct)) and the electron transfer rate constant (k(et)), for different alkanethiol monolayers. An electron tunneling coefficient, beta, of 0.9 A(-1) was calculated for the monolayers on Hg.[on SciFinder (R)]
Meirav Cohen-Atiya and Mandler, Daniel. . 2006. Studying Electron Transfer Through Alkanethiol Self-Assembled Monolayers On A Hanging Mercury Drop Electrode Using Potentiometric Measurements.. Phys. Chem. Chem. Phys.physical Chemistry Chemical Physics, 8, Pp. 4405 - 4409. Abstract
A new approach based on measuring the change of the open-circuit potential (OCP) of a hanging Hg drop electrode (HMDE), modified with alkanethiols of different chain length conducted in a soln. contg. a mixt. of Ru(NH3)62+ and Ru(NH3)63+ is used for studying electron transfer across the monolayer. Following the time dependence of the OCP allowed the extn. of the kinetic parameters, such as the charge transfer resistance (Rct) and the electron transfer rate const. (ket), for different alkanethiol monolayers. An electron tunneling coeff., β, of 0.9 Å-1 was calcd. for the monolayers on Hg. [on SciFinder(R)]
2005
Sharon Fireman-Shoresh, Turyan, Iva , Mandler, Daniel , Avnir, David , and Marx, Sharon . 2005. Chiral Electrochemical Recognition By Very Thin Molecularly Imprinted Sol-Gel Films. Langmuirlangmuir : The Acs Journal Of Surfaces And Colloids, 21, Pp. 7842 - 7. Abstract
Thin films with enantioselective properties for electrochemically active chiral probes were developed. Enantioselectivity was accomplished via molecular imprinting. The films were fabricated through the sol-gel technique and were spin-coated on ITO electrodes. The chiral selectivity recognition was detected using two enantiomer pairs: D- and L-3,4-dihydroxyphenylalanine (D- and L-dopa) and (R)- and (S)-N,N’-dimethylferrocenylethylamine [(R)-Fc and (S)-Fc]. A defined chiral cavity was obtained by selection of functional monomers that interact with the template molecule, followed by its removal. Chiral selection properties were measured by cyclic voltammetry and square wave voltammetry. For both template molecules, very good chiral recognition was revealed by electrochemical measurement. The nonspecific adsorption measured for reference nonimprinted films was negligible (less than 5%). Dopa imprinted films revealed both high sensitivity, by the detection of 1 nM (0.2 ppb) concentration, and excellent selectivity, when challenged with a series of catechol derivatives. Fc-imprinted films were able to detect ca. 2 ppm of the target molecule, with very good enantioselectivity and low nonspecific adsorption. To our knowledge, this is the first report of successful molecular imprinting of a ferrocene derivative.[on SciFinder (R)]