Modulating spectral response of raw photosynthetic pigments via ternary cadmium chalcogenide quantum dots: simultaneous enhancement at green spectrum and inhibition at UV region.

Photosynthesis relies on the absorption of sunlight by photosynthetic pigments (PPs) such as chlorophylls and carotenoids. While these pigments are outstanding at harvesting light, their natural structure restricts their ability to harvest light at specific wavelengths. In this study, Oleic acid-capped CdSeS and CdTeS ternary quantum dots (QDs) were synthesized using a novel two-phase synthesis method. Then, these QDs were used to interact with raw PPs, a mixture of chlorophylls and carotenoids isolated from spinach. Our findings revealed the following: (1) Interacting QDs with raw PPs effectively inhibited the chlorophyll fluorescence of the pigments upon excitation in UV light region (250-400 nm) without causing any damage to their structure. (2) By forming an interaction with QDs, the chlorophyll fluorescence of raw PPs could be induced through excitation with green-light spectrum. (3) The composition of the QDs played a fundamental role in their interaction with PPs. Our study demonstrated that the photophysical properties of isolated PPs could be modified by using cadmium-based QDs by preserving the structure of the pigments themselves.

Ferrocenyl Phthalocyanine as Donor in Non-Poly(3-hexylthiophen-2,5-diyl) Bulk Heterojunction Solar Cell.

Bulk heterojunction (BHJ) solar cells might one day play a vital role in realizing low-cost and environmentally benign photovoltaic devices. In this work, a BHJ solar cell was designed, based on a hexadeca-substituted phthalocyanine (FcPc) with ferrocenyl linked to the phthalocyanine ring. Next, we sought to obtain more quantitative information about the usability of this newly synthesized compound as a donor material in BHJ solar cells. Thus, BHJs with the structure of indium tin oxide/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/FcPc:[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) blend/LiF/Al were fabricated and characterized. The effect of blend ratio (0.5-2.0) on the BHJ solar cell parameters was also investigated. Interesting results were obtained in FcPc and the PCBM blend-based BHJ solar cell under optimized conditions. Our results presented here demonstrate that BHJ devices employing FcPc as a donor has great potential for the development of highly efficient non-poly(3-hexylthiophen-2,5-diyl) photovoltaic devices.

o-Carborane, Ferrocene, and Phthalocyanine Triad for High-Mobility Organic Field-Effect Transistors.

An unsymmetrical zinc phthalocyanine with ferrocenylcarborane linked to the phthalocyanine ring through a phenylethynyl spacer was designed for organic field-effect transistor (OFET). The unsymmetrical phthalocyanine derivatives were characterized using a wide range of spectroscopic and electrochemical methods. In particular, the ferrocenylcarborane structure was unambiguously revealed based on the single-crystal X-ray diffraction analysis. In-depth investigations of the electrochemical properties demonstrated that the ferrocenylcarborane insertion extended the electrochemical character of ferrocenylcarborane-substituted phthalocyanine (7). Moreover, in the anodic potential scans, the oxidative electropolymerization of etynylphthalocyanine (6) and 7 was recorded. To clarify the effect of the insertion of ferrocenylcarborane (2) on the field-effect mobility, solution-processed films of 2, 6, and 7 were used as an active layer to fabricate the bottom-gate top-contact OFET devices. An analysis of the output and transfer characteristics of the fabricated devices indicated that the phthalocyanine derivative functionalized with ferrocenylcarborane moiety has great potential in the production of high-mobility OFET.

Tailoring fluorescent ZIF-8 nanostructures through calix[4]pyrrole modification: tunable size and enhanced organic micropollutant removal capacity.

Whitish-blue light emitting fluorescent ZIF-8 structures were synthesized by means of bis-carboxylate functional calix[4]pyrrole (BCCP) modification. The calix[4]pyrrole concentration was also manipulated to tune the sizes of the ZIF-8 structures. Moreover, the BCCP-modified ZIF-8 samples exhibited enhanced organic micropollutant removal capacity from aqueous solutions.

Ultraprecise control over the photophysical properties of novel amino acid functionalized CdTeS quantum dots and their effect on the emission of yellow-emissive carbon dots.

Cadmium-based quantum dots (QDs) are amongst the most studied nanomaterials due to their excellent photophysical properties, which can be controlled by controlling the size and/or composition of the nanocrystal. However, the ultraprecise control over size and photophysical properties of Cd-based quantum dots and developing user-friendly techniques to synthesize amino acid-functionalized cadmium-based QDs are still the on-going challenges. In this study, we modified a traditional two-phase synthesis method to synthesize cadmium telluride sulfide (CdTeS) QDs. CdTeS QDs were grown with an extremely slow growth-rate (growth saturation of about 3 days), which allowed us to have an ultraprecise control over size, and as a consequence, the photophysical properties. Also, the composition of CdTeS could be controlled by controlling the precursor ratios. The CdTeS QDs were successfully functionalized with a water-soluble amino acid, L-cysteine, and an amino acid derivative, N-acetyl-L-cysteine. Red-emissive L-cysteine-functionalized CdTeS QDs interacted with yellow-emissive carbon dots. The fluorescence intensity of carbon dots increased upon interaction with CdTeS QDs. This study proposes a mild method that allows to grow QDs with an ultraprecise control over the photophysical properties and shows the implementation of Cd-based QDs to enhance the fluorescence intensity of different fluorophores with fluorescence wavelength at higher energy bands.

Aflatoxin B1 Acts as an Effective Energy Donor to Enhance Fluorescence of Yellow Emissive Carbon Dots.

Carbon dots (CDs) are versatile fluorescent nanocrystals with unique optical and structural properties and are commonly used in biosensing, bioimaging, and biomolecule tagging studies. However, fluorescence of CDs is brightest in the wavelength range of 430-530 nm, which overlaps with the autofluorescence range of many eukaryotic cells and makes CDs impractical for in vivo and in vitro imaging studies. Thus, the design of yellow-red emissive CDs with high quantum yield is of importance. In this study, the quantum yield of traditional yellow emissive CDs was enhanced by two different methods: (1) the surface of traditional yellow emissive CDs passivated with a biomolecule, urea, through easy, rapid, inexpensive microwave assisted synthesis methods and (2) a fluorescent biomolecule, aflatoxin B1, used as an energy donor for yellow emissive CDs. In the first method, the quantum yield of the CDs was enhanced to 51%. In the second method, an efficient energy transfer (above 40%) from aflatoxin B1 to the CDs was observed. Our study showed that highly luminescent yellow emissive CDs can be synthesized by simple, rapid microwave assisted synthesis methods, and these CDs are potential candidates to sense aflatoxin B1. Furthermore, our results indicated that Aflatoxin B1 can be considered as an emission booster for CDs.

A Phthalocyanine-ortho-Carborane Conjugate for Boron Neutron Capture Therapy: Synthesis, Physicochemical Properties, and in vitro Tests.

Boronated molecular systems can be applied to boron neutron capture therapy (BNCT). Among these systems, carborane-containing phthalocyanines (Pcs) are the most promising BNCT agents. Herein we report the new zinc (II) complex of the hexacationic Pc 6, which has been obtained as iodide salt through quaternization of the neutral precursor with methyl iodide. Compound 6 was synthesized over a sequence of four steps. The complex, and its precursors as well, were characterized by a combination of spectroscopic techniques, and their structures assessed by 1 H, 13 C, 11 B, and two-dimensional NMR spectroscopy experiments. Together with a marked tendency to aggregate, 6 showed appreciable solubility in water. Singlet oxygen quantum yield (ΦΔ ) of 0.38, and fluorescence quantum yield (ΦF ) of 0.13 were obtained for 6 in a DMF solution. The complex proved to be very effective in enriching UMR-106 cells with 10 B, showing very good performance even in case of very low concentrations exposure, i. e. 1 ppm, that moreover resulted in a mild cytotoxic effect. Such a feature can be related to the polycationic nature of the complex, and hence to the well-known propensity of positively charged species to enter the cellular membrane or to adhere to its external surface.

π-Extended hexadeca-substituted cobalt phthalocyanine as an active layer for organic field-effect transistors.

Due to their flexibility and solution applicability, organic field-effect transistors (OFETs) are considered prominent candidates for application in flexible and low-cost devices. A soluble phthalocyaninato cobalt(ii) complex was designed and synthesized based on a hexadeca-substitution pattern by introducing peripheral phenylethynyl groups and non-peripheral n-butoxy groups. The cobalt phthalocyanine derivative was characterized using a wide range of spectroscopic and electrochemical methods, as well as single-crystal X-ray diffraction analysis. An OFET device was fabricated using a spin-coated film of soluble 1,4,8,11,15,18,22,25-octakisbutoxy-2,3,9,10,16,17,23,24-octakis-ethynyl phenyl phthalocyaninato cobalt(ii) with a bottom-gate top-contact device configuration. The transfer and output characteristics were investigated to evaluate the charge carrier mobility. The mechanisms of the leakage current through the gate dielectric were also investigated, which revealed that the dominant leakage current mechanism is Fowler-Nordheim tunneling.