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BODIPY‐perylene dyads have emerged as useful metal free sensitizers for triplet‐triplet annihilation upconversion (TTAUC), these dyads are capable of efficient triplet generation via spin‐orbit charge transfer intersystem crossing (SOCT‐ISC). This important route to triplet formation requires dyads in which two moieties are oriented perpendicular to each other. In this contribution, we give a deeper insight on the behavior of recently reported BODIPY‐perylene dyads, where BODIPY‐perylene dihedral exhibits a non‐orthogonal dyad geometry. The intersystem crossing of BODIPY‐perylene dyads with and without iodine are investigated using femtosecond transient absorption (fs‐TA) and nanosecond transient absorption (ns‐TA) spectroscopy. The concurrent decay of the singlet charge transfer state (1CT) and rise of triplet states in both the iodinated and non‐iodinated dyads confirms the SOCT‐ISC as the main intersystem crossing pathway despite the altered geometry of the dyads. The presence of an iodine atom on the BODIPY‐moiety enables intersystem crossing 2.6‐times faster and provides a higher triplet yield with respect to dyad without iodine. The upconversion quantum yield (φSUC ${{\phi{} }_{{\rm S}}^{{\rm U}{\rm C}}}$) is 8.4‐times higher in the sample containing iodinated dyad as sensitizer and perylene as annihilator. The triplet‐triplet energy transfer rate (kTTET) is ~8×108 M−1 s−1 for both iodinated and non‐iodinated sensitizer containing TTAUC systems in 1,4‐dioxane. [ABSTRACT FROM AUTHOR]

Covalent functionalisation with alkyl tails is a common method for supporting molecular catalysts and photosensitisers onto lipid bilayers, but the influence of the alkyl chain length on the photocatalytic performances of the resulting liposomes is not well understood. In this work, we first prepared a series of rhenium‐based CO2‐reduction catalysts [Re(4,4'‐(CnH2n+1)2‐bpy)(CO)3Cl] (ReCn; 4,4'‐(CnH2n+1)2‐bpy=4,4'‐dialkyl‐2,2'‐bipyridine) and ruthenium‐based photosensitisers [Ru(bpy)2(4,4'‐(CnH2n+1)2‐bpy)](PF6)2 (RuCn) with different alkyl chain lengths (n=0, 9, 12, 15, 17, and 19). We then prepared a series of PEGylated DPPC liposomes containing RuCn and ReCn, hereafter noted Cn, to perform photocatalytic CO2 reduction in the presence of sodium ascorbate. The photocatalytic performance of the Cn liposomes was found to depend on the alkyl tail length, as the turnover number for CO (TON) was inversely correlated to the alkyl chain length, with a more than fivefold higher CO production (TON=14.5) for the C9 liposomes, compared to C19 (TON=2.8). Based on immobilisation efficiency quantification, diffusion kinetics, and time‐resolved spectroscopy, we identified the main reason for this trend: two types of membrane‐bound RuCn species can be found in the membrane, either deeply buried in the bilayer and diffusing slowly, or less buried with much faster diffusion kinetics. Our data suggest that the higher photocatalytic performance of the C9 system is due to the higher fraction of the more mobile and less buried molecular species, which leads to enhanced electron transfer kinetics between RuC9 and ReC9. [ABSTRACT FROM AUTHOR]

Contemporary devices for glucose monitoring predominantly rely on finger-pricked blood through an enzyme-catalyzed reaction. However, the enzymes are highly expensive, unstable, and require complex procedures for integration with the sensing matrix, rendering strategic replacement by nonenzymatic sensors. Here, a nonenzymatic glucose sensor is developed based on surface engineering of laser scribed graphene (LSG)an immerging 3D patterned graphenethat combines binder-free, highly porous, conducting graphitic carbon network. An easy and green method is developed to engineer the LSG surface by conformal anchoring of copper oxide nanoparticles (CuO NPs) of optimized NP size for enhancing its catalytic efficacy. The device shows excellent nonenzymatic glucose sensing performance (0.4 V detection potential vs printed Ag/AgCl reference electrode, <0.2 s response time, 0.1 μM detection limit, 1 μM-5 mM linearity, and high selectivity). Noteworthy, the device exhibits high stability and reproducibility for glucose in human body fluids (whole blood, serum, sweat, and urine). In addition, conformal transfer of LSG to commercial Scotch brand tape (LSGST) enables wearability of the device on curvilinear body parts, exemplified through miniaturized devices monitoring glucose in sweat directly. These findings pave a new path for a comprehensive personalized healthcare strategy by accurate nonenzymatic detection of glucose from human body fluids. [ABSTRACT FROM AUTHOR]

Herein, we report a single step, anionic surfactant-assisted, low temperature-hydrothermal synthetic strategy of CoO nanoparticles anchored on β-Co(OH)2 nanosheets which show a low overpotential (295 mV @ 10 mA cm−2) for the oxygen evolution reaction (OER). They also demonstrate much better kinetic parameters compared to the state-of-the-art RuO2. Interestingly, under the OER operational conditions (in alkaline medium), the topotactic transformation of α-Co(OH)2 to a stable Brucite-like β-Co(OH)2 phase leads to a synergistic interaction between the β-Co(OH)2 sheets on the CoO nanoparticles for enhancing the OER electrocatalytic activity. [ABSTRACT FROM AUTHOR]

Delaminated 2D sheets of MoSe2 were prepared by liquid phase exfoliation and were embedded over high surface area hydrogen exfoliated graphene (HEG) by a simple technique. The MoSe2/HEG hybrid composite exhibits fast heterogeneous electron-transfer (HET) and a high electrochemically active surface area compared to only HEG. When employed for detection of NADH, it exhibits electrooxidation at a low potential of 150 mV (vs. Ag/AgCl) with high sensitivity of 0.0814 µA⋅µM-1⋅cm2 over a wide linear range (1-280 μM), good selectivity, and a low limit of detection (1 μM). The good performance of the composite is due to the homogeneously dispersed 2D sheets of MoSe2 over large-surface area HEG, which retain its electrochemical activity, prevents restacking, and acts as an electron transfer channel. On the basis of the above analytical requirements and its easy synthesis, the hybrid composite represents a robust material for electrochemical sensing.Schematic of the 2D MoSe2/HEG composite for electrochemical detection of NADH. [ABSTRACT FROM AUTHOR]

BODIPY heterochromophores, asymmetrically substituted with perylene and/or iodine at the 2 and 6 positions were prepared and investigated as sensitizers for triplet-triplet annihilation up conversion (TTA-UC). Single-crystal X-ray crystallographic analyses show that the torsion angle between BODIPY and perylene units lie between 73.54 and 74.51, though they are not orthogonal. Both compounds show intense, charge transfer absorption and emission profiles, confirmed by resonance Raman spectroscopy and consistent with DFT calculations. The emission quantum yield was solvent dependent but the emission profile remained characteristic of CT transition across all solvents explored. Both BODIPY derivatives were found to be effective sensitizers of TTA-UC with perylene annihilator in dioxane and DMSO. Intense anti-Stokes emission was observed, and visible by eye from these solvents. Conversely, no TTA-UC was observed from the other solvents explored, including from non-polar solvents such as toluene and hexane that yielded brightest fluorescence from the BODIPY derivatives. In dioxane, the power density plots obtained were strongly consistent with TTA-UC and the power density threshold, the I th value (the photon flux at which 50 % of ΦTTAUC is achieved), for B2PI was observed to be 2.5x lower than of B2P under optimal conditions, an effect ascribed to the combined influence of spin-orbit charge transfer intersystem crossing (SOCT-ISC) and heavy metal on the triplet state formation for B2PI., (© 2023 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

Covalent functionalisation with alkyl tails is a common method for supporting molecular catalysts and photosensitisers onto lipid bilayers, but the influence of the alkyl chain length on the photocatalytic performances of the resulting liposomes is not well understood. In this work, we first prepared a series of rhenium-based CO 2 -reduction catalysts [Re(4,4'-(C n H 2n+1 ) 2 -bpy)(CO) 3 Cl] (ReC n ; 4,4'-(C n H 2n+1 ) 2 -bpy=4,4'-dialkyl-2,2'-bipyridine) and ruthenium-based photosensitisers [Ru(bpy) 2 (4,4'-(C n H 2n+1 ) 2 -bpy)](PF 6 ) 2 (RuC n ) with different alkyl chain lengths (n=0, 9, 12, 15, 17, and 19). We then prepared a series of PEGylated DPPC liposomes containing RuC n and ReC n , hereafter noted C n , to perform photocatalytic CO 2 reduction in the presence of sodium ascorbate. The photocatalytic performance of the C n liposomes was found to depend on the alkyl tail length, as the turnover number for CO (TON) was inversely correlated to the alkyl chain length, with a more than fivefold higher CO production (TON=14.5) for the C 9 liposomes, compared to C 19 (TON=2.8). Based on immobilisation efficiency quantification, diffusion kinetics, and time-resolved spectroscopy, we identified the main reason for this trend: two types of membrane-bound RuC n species can be found in the membrane, either deeply buried in the bilayer and diffusing slowly, or less buried with much faster diffusion kinetics. Our data suggest that the higher photocatalytic performance of the C 9 system is due to the higher fraction of the more mobile and less buried molecular species, which leads to enhanced electron transfer kinetics between RuC 9 and ReC 9 ., (© 2021 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

Herein, we report a single step, anionic surfactant-assisted, low temperature-hydrothermal synthetic strategy of CoO nanoparticles anchored on β-Co(OH) 2 nanosheets which show a low overpotential (295 mV @ 10 mA cm -2 ) for the oxygen evolution reaction (OER). They also demonstrate much better kinetic parameters compared to the state-of-the-art RuO 2 . Interestingly, under the OER operational conditions (in alkaline medium), the topotactic transformation of α-Co(OH) 2 to a stable Brucite-like β-Co(OH) 2 phase leads to a synergistic interaction between the β-Co(OH) 2 sheets on the CoO nanoparticles for enhancing the OER electrocatalytic activity.