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The development of functional organic materials is crucial for the advancement of various fields, such as optoelectronics, energy storage, sensing, and biomedicine. In this context, we successfully prepared a stable ambipolar perfluoroporphyrin-based polymeric film by electrochemical synthesis. Our strategy involved the synthesis of a novel tetra-p...
A photoactivatable antimicrobial polymeric surface based on a porphycene derivate was efficiently prepared and evaluated to kill pathogenic microorganisms. The development of this self-sterilizing material consisted in the electrochemical polymerization of a peripherally tetra-substituted porphycene bearing benzyl-carbazole groups (Pc-Cbz). The lat...
In this chapter some practical applications of electrochemically generated polymers are described. This chapter is focused on the utilization of electrochemically generated organic polymeric electrodes in electronic and optoelectronic devices. Electropolymerization is a very versatile procedure that can be used to construct organic films over metal...
A heavy‐atom‐free BOPHY‐based photosensitizer (PS) has been obtained as a mixture of two atropisomers. The BOPHY core works as a visible light‐harvesting center and donor antenna, while a fullerene C60 acceptor acts as an effective spin converter and triggers photodynamic action. The dyad is capable of producing reactive oxygen species (ROS) by bot...
A novel BOPHY–fullerene C60 dyad (BP‐C60) was designed as a heavy‐atom‐free photosensitizer (PS) with potential uses in photodynamic treatment and reactive oxygen species (ROS)‐mediated applications. BP‐C60 consists of a BOPHY fluorophore covalently attached to a C60 moiety through a pyrrolidine ring. The BOPHY core works as a visible‐light‐harvest...
A photostable and photodynamic antimicrobial surface was successfully obtained and applied to photoinactivate microorganisms. This approach was based on the synthesis of a fullerene C60 derivative (EDOT-C60) where fullerene C60 is covalently linked to 3,4-ethylenedioxythiophene (EDOT) through a 1,3-dipolar cycloaddition reaction. This dual-function...
Langmuir and Langmuir-Blodgett films holding a synthetic bioinspired wound healing active compound were used as drug-delivery platforms. Palmitic acid Langmuir monolayers were able to incorporate 2-methyltriclisine, a synthetic Triclisine derivative that showed wound healing activity. The layers proved to be stable and the nanocomposites were trans...
Fully polymeric donor-acceptor organic-organic heterojunctions were successfully formed by successive electrochemical polymerization steps. C60 holding polymer acted as an electron acceptor layer when it was electrochemically deposited on the top of a porphyrin based conducting polymer with dendrimeric structure. Porphyrin fluorescence emission que...
A Zn (II) porphyrin monomer modified by four fully π-conjugated side-branches holding eight carbazole residues produces by electrochemical polymerization a hyperbranched polymeric conducting film. The polymer possesses electronic properties that confer to the film the capability for its application in energy storage devices as a supercapacitive mat...
A novel biscarbazol-triphenylamine end-capped dendrimeric zinc(II) porphyrin (DP 5) was synthesized by click chemistry. This compound is a cruciform dendrimer, which bears a nucleus of zinc(II) tetrapyrrolic macrocycle substituted at the meso positions by four identical substituents. These are formed by a tetrafluorophenyl group that possess in the...
A novel biscarbazol-triphenylamine end-capped dendrimeric zinc(II) porphyrin (DP 5) was synthesized by click chemistry. This compound is a cruciform dendrimer, which bears a nucleus of zinc(II) tetrapyrrolic macrocycle substituted at the meso positions by four identical substituents. These are formed by a tetrafluorophenyl group that possess in the...
Ethylenedioxythiophene (EDOT) and Carbazole (CBZ) based conducting polymers holding pendant C60 Buckminster fullerene were formed by electrochemical induced dimerization of four structurally related monomers. Electrochemical and spectroelectrochemical characterization of the thin films clearly indicates the presence of EDOT and CBZ dimers as struct...
Poly(amidoamine) and Poly(propylenimine) dendrimers with different generations and peripheral groups were studied as solubility enhancers and nanocarriers for 7-bromo-2-hydroxy-phenazine N ⁵ ,N ¹⁰ -dioxide. This compound possesses potential antitumoral and anti-trypanosomal activity, but its low solubility in physiological media precludes its possi...
NanoArte ¿cómo vemos lo que el ojo no ve? Editores Un espacio de difusión de nanociencia y nanotecnología e-bo k ISBN 978-987-688-247-7
A family of structurally related π-conjugated star-shape bis-carbazol-triphenylamine end-caped dendrimers was designed, synthetized and characterized as novel organic optoelectronic materials. These compounds hold triphenylamine and carbazole electroactive moieties as dendrimer core and/or periphery groups. Homogeneous and stable electrogenerated p...
Methylammonium lead triiodide (CH3NH3PbI3) perovskite films were generated by chemical conversion of PbO2 layers electrodeposited over NiO hole selective contact, by simple immersion in CH3NH3I isopropanol solution under ambient conditions. 2.4 μm charge carrier diffusion lengths were measured by surface photovoltage, being these very similar to th...
Four organic sensitizers having a di-branched molecular structure D-(π-A)2 (D = para-substituted arylamine, π = 9,9-dibutylfluorene, A = cyanoacrylic acid) were synthesized, characterized, and applied in the development of dye-sensitized solar cells (DSSCs). It was found that the nature of the para-substituent affects the behavior of these sensitiz...
The design and electrosynthesis of electroactive and photoelectroactive polymeric organic thin films holding Zn(II)-porphyrin and Zn(II)-porphyrin-C60 dyad are reported. The presence of carbazole substituents in the meso positions of the tetrapyrolic macrocycle allows the formation of conducting polymers by coupling of electrogenerated carbazole ra...
Organic macromolecules with dendrimeric architectures are polymeric materials potentially useful as nanocarriers for therapeutic drugs. In this work, we evaluate a series of Newkome-type dendrons in Langmuir and Langmuir-Blodgett films as platforms capable of interacting with a potential antitumoral agent. The nanocomposite is proposed as model for...
A first generation dendrimer was evaluated as solubility enhancer of the antitumor compound methyl (5-[propylthio]-1H-benzimidazol-2-yl) carbamate. The dendrimer possess carboxylic acid as terminal groups, which provide high water solubility and a low cytotoxic character. The drug-dendrimer association significantly increases active compound solubi...
The design and synthesis of two potentially electropolymerizable electron donor-acceptor dyes characterized by a cruciform 4,4′-spirobi[cyclopenta[2,1-b:3,4-b′]dithiophene] core is here outlined. The new molecules feature two perpendicularly aligned cyclopentadithiophene branches, each one having an electrodimerizable, electron donor triphenylamine...
A porphyrin-fullerene C60 dyad (TCP-C60) substituted by carbazoyl groups was used to obtain electrogenerated polymeric films on optically transparent indium tin oxide (ITO) electrodes. This approach produced stable and reproducible polymers, holding fullerene units. The properties of this film were compared with those formed by layers of TCP/TCP-C6...
Organic photoactive materials are promising candidates for generation of solar fuels in terms of efficiency and cost. However, their low stability in aqueous media constitutes a serious problem for technological deployment. Here, we present organic photocathodes for generation of hydrogen in aqueous media with outstanding stability. The device reli...
Photoactive heterojunctions formed by por-phyrin polymers were electrochemically generated and analyzed by both transient and spectral dependent surface photovoltage. Indium tin oxide/organic polymer heterojunc-tion photovoltages showed to be dependent on the presence of Zn (II) as central metal on the porphyrin polymer structure. The porphyrin ele...
In this work, we have focused on the study of the influence of the cell composition and architectures on the charge recombination in the PS-based photovoltaic devices, because it directly influences on the photovoltaic parameters, having a special impact on the Open Circuit Voltage, Voc. Therefore, to unraveling the charge recombination mechanisms...
Perovskite solar cells (PSSCs) have recently emerged as a new class of solar cells that have shown a huge increase in energy efficiency conversion (15-16%) [1], since the first report in 2009 [2]. PSSCs use organometallic halide perovskites as light absorbers, and they are very promising solar materials because they can be made by simple solution p...
In this work, we described for the first time a combination of three halides (Cl, Br and I) in complete PS devices. We tuned the optical properties of the PS by modifiyng of the Br/I ratio. A remarkable increase in the Voc and Jsc, and thus in the Efficiency, is observed for the devices containing Cl, however the exact effect of Cl in terms of chan...
The interaction between a 1,2,4-triazine N-oxide derivative, that holds potential antitumor activity under hypoxic conditions, and diverse polyamidoamine (PAMAM) dendrimers were investigated with the purpose of select the most appropriate macromolecule to act as potential molecular carrier of this active compound. The results shows that dendrimers...
We report on the preparation of a series of solution-processed perovskite solar cells based on methylammonium (MA) lead halide derivatives, MAPbX(3), which show tunable optical properties depending on the nature and ratio of the halides employed (X = Cl, Br, and I). Devices have been prepared with different cell architecture, thin film, and mesopor...
Photoactive organic-organic interfaces are formed by electrochemical synthesis. The generation of porphyrin/porphyrin and porphyrin/C60 heterojunctions over indium tin oxide electrodes by successive electropolymerization steps is described. Functionalized C60 buckminsterfullerene holding a carbazol residue and porphyrins containing carbazol and phe...
A new donor/acceptor (D-A) spiro dye (SCPDT1) featuring two bithiophene units, connected through an sp(3)-hybridized carbon atom, was prepared by a multistep synthetic sequence involving the convenient assembly of the spiro system under mild catalytic conditions. The photocurrent spectrum of dye-sensitized solar cells incorporating SCPDT1 covers th...
Molecules with donor (diphenylamine) and acceptor moieties (dicyano or cyanoacrylic acid moieties) were linked by fluorene or spirobisfluorene cores and the chain length has been changed by introducing a thiophene group between fluorene and diphenylamine. Four different kinds of fluorene and spirobisfluorene compounds were adsorbed from highly dilu...
Electroactive end-capped dendritic macromolecules were designed and synthesized. Their structures contain triphenylamine moieties as part of the core or dendrons. The electrogenerated films produced with these monomers behaved as conductive dendritic polymers that can be reversible charged, both in the core and in the peripheral units. The design o...
La presente invención está relacionada con un material de transferencia fotoeléctrico y electro-óptico y su método de manufactura, el elemento de transferencia y su método de manufactura, especialmente apto para su aplicación en celdas solares orgánicas y dispositivos que cambien de color por la aplicación de un voltaje (electrocrómicos).
Surface photovoltage (SPV) measurements were performed with a Kelvin-probe in spirobifluorene-based donor (diphenylamine)–acceptor (dicyano or cyanoacrylic acid moieties) compounds adsorbed from highly diluted solutions onto Au and indium tin oxide electrode surfaces. Strong intramolecular charge separation (negative SPV signals up to more than 0.1...
A series of structurally related sensitizers containing fluorene as a pi-conjugated central core have been synthesized, characterized, and applied in the development of dye-sensitized solar cells (DSSCs). The new electron donor (diphenylamine)-acceptor (cyanoacrylic acid) D-pi-A molecular structures hold perfluoro-tert-butyl substituents in differe...
a b s t r a c t Photovoltaic performance of dye-sensitized solar cell (DSC) devices based on a new titania–graphene paste has been investigated using Impedance Spectroscopy (IS) technique. The results provide key infor-mation about device performance, clarifying that photocurrent increment is not related to lower charge transfer resistance, neither...
Modulated charge separation has been investigated by surface photovoltage spectroscopy in the fixed capacitor arrangement for four different fluorene compounds adsorbed from highly diluted solutions at ultra-thin nanoporous TiO2 (np-TiO2), Au and ITO surfaces. Donor (–N(C6H5)2) and acceptor moieties (–CN, –COOH) were linked by fluorene or spirobisf...
a b s t r a c t New asymmetric porphyrins, with electroactive functionalities were synthesized. 5,15-Bis[4(-N,N-diphenylamino)phenyl]-10,20-bis[3-(N-ethylcarbazoyl)]porphyrin and its Zn(II) derivative allow the electrochemical formation of conjugated, conducting and stable poly-meric films over semitransparent indium–tin oxide surface. The spectral...
A new dyad 9(ZnP-P) has been synthesized linking 5,15-bis(4-carboxyphenyl)-10,20-bis(4-nitrophenyl) porphyrin 4(P) and Zn(II) 5-(4-aminophenyl)-10,15,20-tris(4-methoxylphenyl) porphyrin 8(ZnP) by an amide bond. The structural moieties of dyad 9(ZnP-P) present both different singlet state energy and redox properties. Dyad 9 was designed to improve t...
A series of structurally related sensitizers containing fluorene as a π-conjugated central core have been synthesized, characterized, and applied in the development of dye-sensitized solar cells (DSSCs). The new electron donor (diphenylamine)−acceptor (cyanoacrylic acid) D-π-A molec-ular structures hold perfluoro-tert-butyl substituents in differ-e...
The improvement of aqueous solubility of methyl (5-[propylthio]-1H- benzimidazol-2-yl) carbamate, albendazole (ABZ) using polyamidoamine (PAMAM) dendrimers as solubility enhancers was investigated. Full generation PAMAM dendrimers with amine terminal groups, (G3), with hydroxyl terminal groups (G3OH) and half generation PAMAM dendrimers with carbox...
The electrochemical polymerization conditions for the synthesis of spirobifluorene-based polymer (EF-CN1) films with adequate properties to be applied in an organic light emitting diode (OLED) were studied. We demonstrate that, after optimization in the parameters of electrochemical polymerization, we were able to obtain a conducting polymeric film...
Free base and Pd(II) 5,10,15,20-tetrakis(4-N,N-diphenylaminophenyl)porphyrin form conductive, stable and reproducible electropolymer films. The combined electrochemical and spectroscopic studies show that the electropolymerization mechanism involves the dimerization of triphenylamine units, conducting the formation of a tridimensional structure whe...
Molecules of Pd(II) 5-(4-carboxyphenyl)-10,15,20-tris(4-methylphenyl) porphyrin were adsorbed from highly diluted dichloromethane solution on ultra-thin layers of nanoporous TiO2 and investigated by modulated surface photovoltage (SPV) spectroscopy. An additional transition with a maximum at 2.03 eV appeared in the SPV spectra after moderate anneal...
Charge separation has been investigated at Pd-porphyrin (Pd-P)TiO2 interlaces by surface photovoltage spectroscopy in the Kelvin-probe arrangement. Ultrathin nanoporous TiO2 layers were covered with Pd-P molecules from highly diluted organic solution starting from the submonolayer range. Mechanisms of charge separation including charge separation i...
A new dye, SSD1, featuring two donor/acceptor chromophores aligned in a spiro configuration with two anchoring groups separated at a distance of 10.05 angstrom (closely matching the distance between the adsorption sites of the anatase TiO(2) surface) undergoes efficient dye adherence on TiO(2) films. A dye-sensitized solar cell Incorporating SSD1 e...
Charge separation in gold/spirobifluorene-based donor (triphenylamine)-acceptor (cyano) bipolar systems has been investigated by contact potential difference and surface photovoltage spectroscopy. Organic films were formed on gold electrode by electrochemical polymerization and by dipping in dye solution. The gold surface work function has been cha...
Near-IR dye sensitized solar cells are very interesting due to their potential applications in panchromatic cells, semi-transparent windows and in tandem cells. In this work we show the utilization of axially anchored Si-naphthalocyanine dye in the spectral sensitization of TiO 2 nanostructured photoelectrodes. We report the first successful evalua...
Spectroscopic and photodynamic properties of polymeric films bearing porphyrin units have been studied in both solution containing photooxidizable substrates and in vitro on Escherichia coli and Candida albicans microorganisms. The films were formed by electrochemical polymerization of 5,10,15,20-tetra(4-N,N-diphenylaminophenyl)porphyrin (H2P-film)...
This Article describes the synthesis and physical properties of two bipolar starburst monomers: 1,3,5-tris{5-(7-(carbazol-9-yl)-(9,9′-spirobifluoren-2-yl)-1,3,4-oxadiazol-2-yl}benzene (OXD-CBZ) and 1,3,5-tris[7-diphenyl-(9,9′-spirobifluorene)-1,3,4-oxadiazoyl]benzene (OXD-DPA) featuring an electron-deficient tris(1,3,4-oxadiazole)phenylene ring as...
Ru(dcbpyH2)2(NCS)2 molecules have specific binding sites for TiO2 and Au surfaces and a large dipole moment what makes them attractive for engineering of Schottky junctions. The rectification of the junction conditioned with a monolayer of Ru(dcbpyH2)2(NCS)2 molecules increased by several orders of magnitude in comparison to the bare TiO2/Au juncti...
Oxidative electrochemical pretreatment on glassy carbon (GC) electrodes in aqueous media produces changes in the relative
densities of oxidized species present on the material surface. These changes vary with both applied potential and time procedure.
The GC surface oxidation treatment not only increases the oxygen-containing group coverage but als...
We have synthesized a novel 9,9′-spirobifluorene-cored donor-acceptor (D-A) bichromophore system in which the electron-donating (D) moieties are triphenylamine (TPA) and carbazole (CBZ) groups and the electron-withdrawing (A) moieties are 1,3,4-oxadiazole (OXD) groups. The electron-deficient OXD groups efficiently blocked the radical cations deloca...
The TiO2/P-C-60 ( porphyrin - C-60 fullerene dyad) system has been investigated by surface photovoltage spectroscopy under steady state ( in the Kelvin-probe arrangement) and under chopped light illumination ( in the capacitor arrangement). In contrast to TiO2 with adsorbed porphyrins (M-5-(4-carboxyphenyl)-10,15,20-tris(4-methylphenyl) porphyrin)...
Charge separation processes in metal-free tetraphenyl-porphyrin (H2TPP) layers deposited on Au substrate have been studied using surface photovoltage spectroscopy. The results show that dissociation of excitons at the H2TPP/Au interface causes charge separation by holes escaping from the interface region. This interface features a potential barrier...
In this work, we study the characteristics of dye-sensitized solar cells using an ionic liquid as the electrolyte and compare them with the response of a solvent-containing electrolyte cell. Impedance spectroscopy is used to derive the key circuit elements determining the photovoltaic performance of the cell. On the basis of this data, photocurrent...
Carotenoids (Car) act as “wires” that discharge unwanted electrons in the reaction center of higher plants. One step in this “side-path” electron conduction is thought to be mediated by Car oxidation. We have carried out direct measurements of the conductance of single-Car molecules under potential control in a membrane-mimicking environment, and w...
The synthesis and photophysical, electrochemical, and spectroelectrochemical characterization of a novel donor−acceptor (D−A) bichromophore system composed of two D−A segments linking through a spiro center are reported. The electron-donating (D) moieties are triphenylamine (TPA) groups, whereas the electron-withdrawing (A) moieties are cyano group...
Free-base (P), Zn(II) (P(Zn)), Cu(II) (P(Cu)), Pd(II) (P(Pd)), Ni(II) (P(Ni)), and Co(II) (P(Co)) 5-(4-carboxyphenyl)-10,15,20-tris(4-methylphenyl) porphyrins were designed and synthesized to be employed as spectral senzitizers in photoelectrochemical cells. The dyes were studied adsorbed on SnO(2) nanocrystalline semiconductor and also in Langmuir...
A electron donor–acceptor porphyrin dyad (PZn–P) was synthesized by linking an electron acceptor porphyrin; 5,15-bis(4-carboxyphenyl)-10,20-bis(4-nitrophenyl) porphyrin (P) and an electron donor porphyrin; Zn(II) 5-(4-aminophenyl)-10,15,20-tris(4-methoxylphenyl) porphyrin (PZn) by amide bond. PZn–P dyad – thin SnO2 nanocrystalline semiconductor fil...
The electrochemistry of a series of non-symmetric synthetic carotenoids, with different conjugated double bounds chain lengths (5 to 11) is reported. The values of the first oxidation potentials of the carotenoids were evaluated by digital simulation of the experimental cyclic voltammograms. There is a clear relationship between calculated (AM1) HO...
A new dyad 9 (ZnP-P) has been synthesized linking 5,15-bis(4-carboxyphenyl)-10,20-bis(4-nitrophenyl) porphyrin 4 (P) and Zn(II) 5-(4-aminophenyl)-10,15,20-tris(4-methoxylphenyl) porphyrin 8 (ZnP) by an amide bond. The structural moieties of dyad 9 (ZnP-P) present both different singlet state energy and redox properties. Dyad 9 was designed to impro...
The generation of photoelectrical effects through the spectral sensitization of wide band gap semiconductor electrode by the excitation of a series of novel synthetic organic molecules is reviewed. Natural Photosynthetic-related supramolecular systems where designed and constructed in order to obtain "antenna" and intramolecular charge transfer pro...
Transport of calcium ions across membranes and against a thermodynamic gradient is essential to many biological processes, including muscle contraction, the citric acid cycle, glycogen metabolism, release of neurotransmitters, vision, biological signal transduction and immune response. Synthetic systems that transport metal ions across lipid or liq...
Zn(II) porphyrin–C60 dyad (7) was synthesized by the coupling reaction between Zn(II) 5-(4-aminophenyl)-10,15,20-tris(4-methoxylphenyl)porphyrin (4) and 1,2-dihydro-1,2-methanofullerene[60]-61-carboxylic acid (6). The electron-donor capacity of the porphyrin moiety in dyad 7 is enhanced by methoxy group substitution on the macrocycle peripheries an...
The generation of photoelectrical effects through the spectral sensitization of wide band gap (SnO2) nanostructured semiconductor electrode by the excitation of a novel porphyrin−fullerene (P−C60) dyad is reported. P−C60 was synthesized from 5-(4-amidophenyl)-10,15,20-tris(4-methoxylphenyl) porphyrin (P) linked to 1,2-dihydro-1,2-methoxyphenyl [60]...
Due to the complexity of the glassy carbon (GC) | electrolyte interface, several physical, chemical, and electrochemical activation
methods have been developed, mainly to obtain both high activities for heterogeneous charge transfer and reproducibility.
One of the most simple and widely used methods in the pretreatment of GC electrodes is oxidation...
A convenient procedure for the synthesis of a new porphyrin–C 60 dyad via the reaction between 5-(4-aminophenyl)-10,15,20-tris(4-methoxyphenyl) porphyrin and a C 60 carboxylic acid is described. The results of preliminary photo-electrochemical studies on nanostructured SnO 2 electrodes coated with the new dyad suggest that the resultant substrate i...
LB films of an amphipathic carotenoid, 7‘-apo-7‘-(4-aminophenyl)-β-carotene (H2APC), deposited on semiconducting transparent ITO electrodes, when immersed in electrolyte-containing benzoquinone (Q) and illuminated, produced photocurrents that were measured over the spectral range of 350−700 nm. The generated photocurrent was investigated as a funct...
Sensitized photocurrent generation is observed with a porphyrin dyad (PZn-P) and its structural moieties: 5-(4-carboxyphenyl)-10,15,20-tris(4-methylphenyl) porphyrin (P) and Zn(II) 5-(4-carboxyphenyl)-10,15,20-tris(4-methylphenyl) porphyrin (PZn). The dyes were adsorbed to saturation on a nanocrystalline SnO2 thin film, employed as working electrod...
A convenient procedure for the synthesis of porphyrin derivative dyads is described. The dyads consist of a free base porphyrin covalently linked to a zinc porphyrin or ferrocene by an amide bond. 5-(4-Substituted phenyl)-10,15,20-tris(4-methylphenyl) porphyrins were synthesized from meso-(4-methylphenyl) dipyrromethanes 1, which was obtained with...
The synthesis of meso-tetraphenylporphyrin (TPP) and its application in a solar- energy conversion device are described as an undergraduate laboratory experiment. In the first part of the exercise, a convenient procedure for the synthesis of TPP is presented. In the second section of the experiment, the construction of a high-efficiency photoelectr...
Glassy carbon (GC) electrodes were modified by polishing and electrochemical pre-treatment (ECP) in an acidic aqueous medium to obtain a reproducible kinetic response. The surface state was characterised by an electrochemical parameter, Q0, which has been demonstrated to be proportional to the number of surface sites susceptible of oxidation. A pro...
Under visible illumination, a thin film of nanocrystalline TiO2 coated with an adsorbed substituted-Ru(bpy)3+2-labeled polyimide 1 produces a sensitized photocurrent when spin-coated on a conductive ITO support. The magnitude of the observed anodic photocurrent defines the efficiency of charge injection from the adsorbed dye to the nanoparticle and...
Modest fill factors (∼0.2) and efficiencies for sensitized photocurrent generation are observed with porphyrins adsorbed to saturation on a nanocrystalline SnO2 thin film employed as the working electrode in a photoelectrochemical cell. No dye aggregation is observed at the metal oxide/adsorbate interface, and no advantage in the photosensitization...
Composite nanocrystalline SnO2 thin films layered with a polyimide sensitizer to which is attached a Ru(bpy)32+ derivative were prepared by spin-coating. Photophysical and electrochemical properties of such composite films, when formulated as polymer-modified electrodes, are described. Excitation spectra of both composite films and of the dissolved...
Two approaches to eliciting photoelectrochemical reactions from carotenoids are being pursued. One uses LB films of amphipathic carotenoids deposited on semiconducting electrodes which are immersed in electrolytes containing electron donors or acceptors. Photocurrents are observed and their action spectra implicate the excited carotenoid pigment, p...
Langmuir−Blodgett (LB) films of an amphipathic carotenoid, 7‘-apo-7‘-(4-carboxyphenyl)-β-carotene (ACC), were deposited on semiconducting transparent ITO electrodes which were then immersed in electrolyte containing benzoquinone (Q) or hydroquinone (QH2). Photocurrents were measured over the spectral range 350−700 nm. The action spectra implicate t...
The fundamental aspects that condition the electrochemical response of glassy carbon (GC) electrodes are the bulk properties and the surface treatment. In previous work we reported an electrochemical treatment in 1 M H2SO4. It consisted of cycling the electrode between −0.50 and 1.86 V (vs. SCE). The same procedure is used in this work. This treatm...
