Dye-sensitized solar cells based on iodide/triiodide (I(-)/I(3)(-)) electrolytes are viable low-cost alternatives to conventional silicon solar cells. However, as well as providing record efficiencies of up to 12.0%, the use of I(-)/I(3)(-) in such solar cells also brings about certain limitations that stem from its corrosive nature and complex two-electron redox chemistry. Alternative redox mediators have been investigated, but these generally fall well short of matching the performance of conventional I(-)/I(3)(-) electrolytes. Here, we report energy conversion efficiencies of 7.5% (simulated sunlight, AM1.5, 1,000 W m(-2)) for dye-sensitized solar cells combining the archetypal ferrocene/ferrocenium (Fc/Fc(+)) single-electron redox couple with a novel metal-free organic donor-acceptor sensitizer (Carbz-PAHTDTT). These Fc/Fc(+)-based devices exceed the efficiency achieved for devices prepared using I(-)/I(3)(-) electrolytes under comparable conditions, revealing the great potential of ferrocene-based electrolytes in future dye-sensitized solar cells applications. This improvement results from a more favourable matching of the redox potential of the ferrocene couple with that of the new donor-acceptor sensitizer.

Protein inactivation by reactive oxygen species (ROS) such as singlet oxygen ((1)O2) and superoxide radical (O2(•-)) is considered to trigger cell death pathways associated with protein dysfunction; however, the detailed mechanisms and direct involvement in photodynamic therapy (PDT) have not been revealed. Herein, we report Ir(III) complexes designed for ROS generation through a rational strategy to investigate protein modifications by ROS. The Ir(III) complexes are effective as PDT agents at low concentrations with low-energy irradiation (≤ 1 J cm(-2)) because of the relatively high (1)O2 quantum yield (> 0.78), even with two-photon activation. Furthermore, two types of protein modifications (protein oxidation and photo-cross-linking) involved in PDT were characterized by mass spectrometry. These modifications were generated primarily in the endoplasmic reticulum and mitochondria, producing a significant effect for cancer cell death. Consequently, we present a plausible biologically applicable PDT modality that utilizes rationally designed photoactivatable Ir(III) complexes.

Dye regeneration and charge recombination in dye-sensitized solar cells Dye regeneration and charge recombination in dye-sensitized solar cells with Dye regeneration and charge recombination in dye-sensitized solar cells with ferrocene derivatives as redox mediators ferrocene derivatives as redox mediators

The mitochondria-associated membrane (MAM) has emerged as a cellular signaling hub regulating various cellular processes. However, its molecular components remain unclear owing to lack of reliable methods to purify the intact MAM proteome in a physiological context. Here, we introduce Contact-ID, a split-pair system of BioID with strong activity, for identification of the MAM proteome in live cells. Contact-ID specifically labeled proteins proximal to the contact sites of the endoplasmic reticulum (ER) and mitochondria, and thereby identified 115 MAM-specific proteins. The identified MAM proteins were largely annotated with the outer mitochondrial membrane (OMM) and ER membrane proteins with MAM-related functions: e.g., FKBP8, an OMM protein, facilitated MAM formation and local calcium transport at the MAM. Furthermore, the definitive identification of biotinylation sites revealed membrane topologies of 85 integral membrane proteins. Contact-ID revealed regulatory proteins for MAM formation and could be reliably utilized to profile the proteome at any organelle–membrane contact sites in live cells.

The ECL behavior of bis-cyclometalated (pq) 2 Ir(LX) complexes, in which pq is a 2-phenylquinoline anion and LX is a monoanionic bidentate ligand (e.g., acetylacetonate, picolinate, etc.), and the specific influences of the electrochemical stability and photoluminescence quantum yield (PL QY) of luminophores on ECL generation have been investigated. In this study, efficient ECLs, some of which even approached Φ ECL ) 0.88 (18× higher than that of Ru(bpy) 3 2+ ), have been observed in the annihilation process. The simultaneous accumulation to excited singlet S 1 and triplet T 1 states and the spin-orbit coupling characteristics of transition metal complexes are expected to produce efficient annihilation ECL, which permits the high efficiency to exceed PL QY. A cyclic voltammetric study has revealed that the ECL intensity depends primarily on the electrochemical stability of the redox precursors of (pq) 2 Ir(LX)s. For example, (pq) 2 Ir(acac) (acac ) acetylacetonate anion), which shows irreversible reduction, has produced efficient ECL during the oxidativereductive process but less intense ECL during both the annihilation and reductive-oxidative processes. In the oxidative-reductive process, (pq) 2 Ir(LX)s also produces efficient ECL reacting with tri-n-propylamine radical precursors (TPA′ • ). During the oxidative-reductive process, (pq) 2 Ir(LX)/TPA couples undergo many competitive pathways involving both heterogeneous and homogeneous reactions. The tendency of ECL intensities with respect to their PL QYs is more complicated than that in the case of the annihilation process. These findings provide useful information on the fundamental ECL studies and the search for new ECL luminophores or practical ECL applications, such as analysis based on ECL and electroluminescent devices.

Here, we introduce regenerated fibers of chitin (Chiber), the second most abundant biopolymer after cellulose, and propose its utility as a nonwoven fiber separator for lithium metal batteries (LMBs) that exhibits an excellent electrolyte-uptaking capability and Li-dendrite-mitigating performance. Chiber is produced by a centrifugal jet-spinning technique, which allows a simple and fast production of Chibers consisting of hierarchically aligned self-assembled chitin nanofibers. Following the scrutinization on the Chiber-Li-ion interaction via computational methods, we demonstrate the potential of Chiber as a nonwoven mat-type separator by monitoring it in Li-O and Na-O cells.

Metal–organic framework (MOF) nanoparticles with high porosity and greater tunability have emerged as new drug delivery vehicles. However, premature drug release still remains a challenge in the MOF delivery system. Here, we report an enzyme-responsive, polymer-coated MOF gatekeeper system using hyaluronic acid (HA) and PCN-224 nanoMOF. The external surface of nanoMOF can be stably covered by HA through multivalent coordination bonding between the Zr cluster and carboxylic acid of HA, which acts as a gatekeeper. HA allows selective accumulation of drug carriers in CD44 overexpressed cancer cells and enzyme-responsive drug release in the cancer cell environment. In particular, inherent characteristics of PCN-224, which is used as a drug carrier, facilitates the transfer of the drug to cancer cells more stably and allows photodynamic therapy. This HA-PCN system enables a dual chemo and photodynamic therapy to enhance the cancer therapy effect.

Various iridium complexes consisting of phenylpyrazole (ppz) ligands and isoquinolinecarboxylic acids (iq) as ancillary ligands were designed by energy band-gap calculations via ab initio calculations and synthesized to give rise to various emission wavelengths as expected. Fine color tuning was achieved through varying the position of the methyl substituent on the phenylpyrazole moiety with HOMO electron densities. Additional color tuning was made possible by altering the LUMO through the use of different ancillary ligands such as 1-isoquinolinecarboxylic acid (1iq) and 3-isoquinolinecarboxylic acid (3iq).