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1. Catalytic Degradation of Organic Dyes Indicates Anti-Proliferative Effects of Magnetoelectric Nanoparticles

   https://doi.org/10.1007/s11664-025-11843-5  

   Shotbolt, Max; Zhu, Emily; Andre, Victoria; Zhang, Elric; Duran, Isabelle; Bryant, John; El-Rifai, Wael; Liang, Ping; Khizroev, Sakhrat (March 2025, Journal of Electronic Materials)

   Abstract Over the past decade, magnetoelectric nanoparticles (MENPs) have proven effective in generating local electric fields in response to stimulation with a magnetic field. The applications of such nanoparticles are many and varied, with examples of prior research including use for on-demand drug release, wireless modulation and recording of neural activity, and organic dye degradation. This study investigates the potential for organic dye degradation to be used as a rapid and efficient screening tool to detect the magnetoelectric effect of MENPs, and how the results of such a test mirror the antiproliferative effect of said nanoparticles. Trypan blue was selected as an azo dye to test for dye degradation. Vials of the dye were treated with CoFe2O4@BaTiO3 core-shell MENPs of varying characteristics, both with and without concurrent 1-kHz 250-Oe magnetic stimulation. Dye degradation was measured using ultraviolet (UV)-vis spectroscopy. Dye degradation efficacy varied with varying nanoparticle synthesis parameters. As controls, nanoparticles of the same composition, but with an insignificant magnetoelectric effect, were used. SKOV-3 ovarian cancer cells were then treated with the same nanoparticles, and viability was measured with an adenosine triphosphate (ATP) assay. These measurements show a decrease in cell viability up to 60.3% of control (p = 0.0052), which mirrored the efficacy of dye degradation of up to 69.8% (p = 0.0037) in each of the particle variants, demonstrating the value of azo dye degradation as a simple screening test for MENPs, and showing the potential of MENPs used as wirelessly controlled nanodevices to allow targeted electric field-based treatments. 

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2. Selective and Sensitive Dual Chromogenic Cyanide and Fluorescent Azide Probe

   https://doi.org/10.3390/photochem5020012  

   Hijji, Yousef M; Rajan, Rajeesha; Shraim, Amjad M; Attili, Bassam; Uota, Sisay; Abebe, Fasil (June 2025, Photochem)

   IR-780 is a heptamethine cyanine dye that exhibits strong absorbance in the near-infrared region. Herein, we report IR-780 dye as a dual sensor for chromogenic cyanide detection and azide’s fluorogenic sensing in acetonitrile. Cyanide and hydroxide cause instant, dramatic color changes in the dye solution from green to yellow and dramatic spectral changes in the UV-Vis spectrum. The interaction of cyanide and hydroxide with the dye caused a dramatic decrease in the intensity of the strong absorption band at 780 nm and a concomitant band appearance at 435 nm. Other monovalent ions, including fluoride, chloride, bromide, iodide, dihydrogen phosphate, thiocyanate, acetate, and dihydrogen arsenate, caused no significant color or spectral changes. UV-Vis studies showed that the IR-780 dye is sensitive and selective to both ions. The detection limits for cyanide and azide are 0.39 µM and 0.50 µM, respectively. Interestingly, the IR-780 dye exhibited strong fluorescence at 535nm upon interaction with azide, while its initial emission at 809 nm was quenched. Both UV-Vis and fluorescence spectroscopy accomplished the detection of cyanide and azide using IR-780. Furthermore, the sensor’s effectiveness in fluorescence imaging of intracellular CN⁻ ions is demonstrated in live HeLa cells. 

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3. Excitonically coupled cyanine dye dimers as energy transfer relays on DNA templates

   Sebastián Díaz, Young Kim (March 2024, ACS applied optical materials)

   An attractive strategy to improve the energy transfer properties of synthetic dye networks is to optimize the excitonic coupling between the dyes to increase energy transfer rates. To explore this possibility, we investigate the use of J-like cyanine dye dimers (Cy3 and Cy5 dimers) on DNA duplexes as energy transfer relays in molecular photonic wires. This approach is based on using the collective emission dipole of a J-dimer to enhance the FRET rate between the dimer relay and a remote acceptor dye. Experimentally, we find that in room temperature aqueous buffer conditions the dimer relay provided no benefit in energy transfer quantum yield relative to a simple monomer relay. Further investigation led us to determine that enhanced non-radiative relaxation, non-ideal dye orientation within the dimer, and unfavorable dye orientation between the dimer and the acceptor dye limit energy transfer through the dimer relay. We hypothesized that non-radiative relaxation was the largest factor, and demonstrated this by placing the sample in a viscous solvent or cooling the sample, which dramatically improved energy transfer through the J-like dimer relay. Similar to how the formation of DNA-templated J-like dimers has improved, the practical use of J-like dimers to optimize energy transfer quantum efficiency will require improvements in the ability to control orientation between dyes to reach its full potential. 

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4. An automated quantum chemistry-driven, experimental characterization for high PCE donor–π–acceptor NIR molecular dyes

   https://doi.org/10.1039/D3DD00023K  

   Santaloci, Taylor J; Meador, William E; Wallace, Austin M; Valencia, E Michael; Rogers, Blake N; Delcamp, Jared H; Fortenberry, Ryan C (October 2023, Digital Discovery)

   A readily accessible dye molecule with potential properties well-beyond the state-of-the-art for dye-sensitized solar cells is realized from extensive quantum chemical characterization of nearly 8000 stochastically-derived novel molecules. 

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5. BODIPY Chemisorbed on SnO2 and TiO2 Surfaces for Photoelectrochemical Applications

   https://doi.org/10.1021/acsami.3c18827  

   Jayworth, Josephine A.; Decavoli, Cristina; Capobianco, Matt D.; Menzel, Jan Paul; Adler, Spencer R.; Kocoj, Conrad A.; Freeze, Jessica G.; Crabtree, Robert H.; Guo, Peijun; Batista, Victor S.; et al (March 2024, ACS Applied Materials & Interfaces)

   Advancement toward dye-sensitized photoelectrochemical cells to produce solar fuels by solar-driven water splitting requires a photosensitizer that is firmly attached to the semiconducting photoelectrodes. Covalent binding enhances the efficiency of electron injection from the photoexcited dye into the metal oxide. Optimization of charge transfer, efficient electron injection, and minimal electron-hole recombination are mandatory for achieving high efficiencies. Here, a BODIPY-based dye exploiting an innovative surface-anchoring mode via boron is compared with a similar dye bound by a traditional carboxylic acid anchoring group. Through terahertz and transient absorption spectroscopic studies, along with GFN-xTB calculations, we find that, when compared to the traditional carboxylic acid anchoring group, electron injection of boron-bound BODIPY is faster into both TiO2 and SnO2. Although the surface coverage is low compared with carboxylic acids, the binding stability is improved over a wide range of pH. Subsequent photoelectrochemical studies using a sacrificial electron donor showed this combined dye and anchoring group maintained photocurrent with good stability over long-time irradiation. This recently discovered binding mode of BODIPY shows excellent electron injection and good stability over time, making it promising for future investigations. 

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