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Fiber organic electrochemical transistors (OECTs) hold significant promise for in vivo bio-signal amplification due to their minimally invasive and seamless integration with biological tissues. However, their use in monitoring rapid physiological changes, such as electrophysiological signals, has been constrained by slow response time, arising from their extensive channel dimensions. Here, we introduce a novel fiber OECT designed with a micro-scale vertical channel (F-vOECT) that substantially reduces the response time by an order of magnitude to 12 ms and achieves a maximum transconductance of 16 mS at zero gate bias, marking a substantial improvement over previous fiber OECTs. This compact and flexible fiber device demonstrates robust performance under cyclic switching, dynamic deformation and exhibits excellent biocompatibility. When subcutaneously implanted in rats, the F-vOECT enables stable, continuous electrocardiogram monitoring for 7 days, successfully identifying episodes of atrioventricular block. These capabilities illustrate its potential for clinical electrophysiological diagnostics. The design strategy of F-vOECT opens new avenues for developing fast-responsive fiber bioelectronic devices. [ABSTRACT FROM AUTHOR]

Flexible fiber electrodes offer new opportunities for bioelectronics and are reliable in vivo applications, high flexibility, high electrical conductivity, and satisfactory biocompatibility are typically required. Herein, we present an all-metal flexible and biocompatible fiber electrode based on a metal nanowire hybrid strategy, i.e., silver nanowires were assembled on a freestanding framework, and further to render them inert, they were plated with a gold nanoshell. Our fiber electrodes exhibited a low modulus of ∼75 MPa and electrical conductivity up to ∼4.8 × 106 S m−1. They can resist chemical erosion with negligible leakage of biotoxic silver ions in the physiological environment, thus ensuring satisfactory biocompatibility. Finally, we demonstrated the hybrid fiber as a neural electrode that stimulated the sciatic nerve of a mouse, proving its potential for applications in bioelectronics. [ABSTRACT FROM AUTHOR]

Since the abuse of antibiotic oxytetracycline (OTC) poses a serious threat to the environment and human health, it is of great importance to develop sensitive fluorescent probes for its rapid and in situ detection. Herein, a dual fluorescence response probe based on an aluminum-incorporated metal–organic framework (MOF) was presented for OTC assay. Unlike internal references that demonstrate an independent and stable fluorescence signal intensity in traditional dual-emissive probes, the fluorescence of rhodamine B immobilized in a prepared probe was gradually enhanced at a 585 nm emission wavelength with increasing concentrations of OTC under 405 nm excitation, while OTC also experienced an obvious fluorescence enhancement at a 521 nm emission wavelength due to a molecular conformation transition from the twisted to the extended state, realizing a molecular conformational transition-induced dual fluorescence enhancement for OTC detection under a single excitation wavelength. In addition to the mechanism exploration and double linear range for OTC quantification with nM level detection limits in solution, a paper-based portable test strip was successfully fabricated by loading the probe on glass fiber filter paper with an obvious fluorescence color change from orange to yellow upon increasing the addition of OTC. We expect that the proposed probe in this work would provide an example for the design of organic fluorophore-based sensors exhibiting multiple fluorescence responses under a single excitation. [ABSTRACT FROM AUTHOR]

A new method for the synthesis of 3-arylindoles has been developed by visible light mediated dual gold/photoredox catalysis. This transformation has many features such as cascade catalysis, high efficiency, redox-neutral reaction conditions and good functional group tolerance. The reaction proceeds through the photoredox-promoted formation of an electrophilic arylgold(iii) intermediate that undergoes coupling with the arylamine nucleophile. [ABSTRACT FROM AUTHOR]

The synthesis, characterization and photoluminescent properties of a dinuclear Ir complex with a μ-η1:η2-phenylquinolyl bridge and an end-on dinitrogen ligand are reported herein. DFT studies on its electronic structure and photophysical properties are also presented. [ABSTRACT FROM AUTHOR]

Since the abuse of antibiotic oxytetracycline (OTC) poses a serious threat to the environment and human health, it is of great importance to develop sensitive fluorescent probes for its rapid and in situ detection. Herein, a dual fluorescence response probe based on an aluminum-incorporated metal-organic framework (MOF) was presented for OTC assay. Unlike internal references that demonstrate an independent and stable fluorescence signal intensity in traditional dual-emissive probes, the fluorescence of rhodamine B immobilized in a prepared probe was gradually enhanced at a 585 nm emission wavelength with increasing concentrations of OTC under 405 nm excitation, while OTC also experienced an obvious fluorescence enhancement at a 521 nm emission wavelength due to a molecular conformation transition from the twisted to the extended state, realizing a molecular conformational transition-induced dual fluorescence enhancement for OTC detection under a single excitation wavelength. In addition to the mechanism exploration and double linear range for OTC quantification with nM level detection limits in solution, a paper-based portable test strip was successfully fabricated by loading the probe on glass fiber filter paper with an obvious fluorescence color change from orange to yellow upon increasing the addition of OTC. We expect that the proposed probe in this work would provide an example for the design of organic fluorophore-based sensors exhibiting multiple fluorescence responses under a single excitation.

The structural properties such as high specific surface area, good electrical conductivity, rich-defects of the catalyst surface guarantee outstanding catalytic performance and durability of oxygen reduction reaction (ORR) electrocatalysts. It is still a challenging task to construct ORR catalysts with excellent performance. Herein, we have reported column-like MoS 2 /rGO with defect-rich ultrathin nanosheets prepared by a convenient solvothermal method. The structure and composition of MoS 2 /rGO are systematically investigated. MoS 2 /rGO shows a remarkable electrocatalytic performance, which is characterized by an outstanding onset potential of 0.97 V, a half-wave potential of 0.83 V, noticeable methanol tolerance, and durability of 93.7% current retention, superior to commercial Pt/C. The ORR process occurring on MoS 2 /rGO is a typical four electron pathway. Therefore, this study achieves the design of a low-cost, highly efficient and stable nonprecious metal ORR electrocatalyst in alkaline media., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

In this paper, a C-F bond activation reaction of a chloro-bridged iridium(III) dimer (dfppy)(2)Ir(μ-Cl)(2)Ir(dfppy)(2) (1) (dfppy denotes 2-(4,6-difluorophenyl)pyridyl) in the presence of sodium methoxide has been reported, leading to the formation of a heteroleptic cyclometalated iridium(III) fluorophenylpyridine complex 2. HPLC-mass analysis confirmed the release of formaldehyde in the product mixture. When sodium benzyloxide was used as the base, complex 2 was also generated with the release of a benzaldehyde derivative. Complex 2 has been fully characterized by (1)H-NMR, (19)F-NMR and X-ray crystallographic methods, confirming the partial loss of one of the fluorine atoms on one of the cyclometalated phenylpyridyl ligands. Photophysical studies of complex 2 show that it has a similar absorption spectrum to that of Ir(III)(dfppy)(3). However, the emission spectrum shows a red shift maximum emission band at 478 nm due to the loss of a single fluorine atom, highlighting the critical effect of fluorine on the photoluminescence of these Ir(III) complexes. Finally, intensive mechanistic studies including HPLC-mass analysis, (1)H-NMR, and (19)F-NMR studies demonstrate that the formation of complex 2 should involve a critical β-hydride elimination of Ir(III)-alkoxide intermediate and the participation of Ir-hydride and/or Ir-fluoride intermediates.

A systematic theoretical study on reaction mechanisms for copper(I)-catalyzed C-O coupling of phenols with aryl bromides is reported herein. Through evaluation of the relative concentrations of possible copper species in reaction solution and reactivity study of these copper species with aryl halides in the context of several commonly proposed mechanisms for copper(I)-catalyzed Ullmann reactions, we propose that the active copper catalyst should be a neutral (L)Cu(I)-OAr (L denotes an ancillary ligand; OAr denotes an aryloxide ligand) species in nonpolar solvent and Cu(OAr)(2)(-) anion in highly polar solvent. In the reaction solution, these two kinds of copper species should be in equilibrium, the direction of which is highly dependent on the polarity of the solvent. For both kinds of copper species, a halogen atom transfer mechanism is favored where an initial halogen atom transfer from phenyl bromide to the Cu(I) center occurs, resulting in the formation of Cu(II)(OAr)(Br) and a phenyl radical. Subsequent rapid attack of this phenyl radical to the aryloxide ligand bound to copper(II) would yield the coupling product and Cu(I)(Br) species, which can be readily converted to the active Cu(I)-OAr species in the presence of phenols and base. Other mechanisms such as oxidative addition, single electron transfer and σ-bond metathesis mechanisms all possess activation barriers which are too high, rendering them kinetically unfavorable. Electronic effects on phenol rings reveal that electron-donating substituents accelerate the coupling of (phen)Cu(I)(OAr) with aryl halides whereas electron-withdrawing substituents lead to much higher activation barriers, which is consistent with experimental findings and thus lends further support for such a halogen atom transfer mechanism. In view of the widely accepted oxidative addition/reductive elimination mechanism for analogous copper(I)-catalyzed coupling of N-nucleophiles with aryl halides, our results here highlight that the reaction mechanism of copper(I)-catalyzed Ullmann reactions is highly dependent on the nature of the nucleophile and different kinds of nucleophiles can be involved in different mechanisms.

In this paper, copper(I) amidate complexes (2-3), proposed intermediates in copper-catalyzed Goldberg reaction, have been prepared and characterized by elemental analysis, IR, (1)H NMR and X-ray crystallography. Ancillary ligand bis(diphenylphosphino)ferrocene (dppf) has contributed greatly to the stability of the copper-amidate complexes due to its strong chelating ability and weak intermolecular interactions. Thermal gravimetric analyses are carried out to determine the thermal competency of complexes 2-3 as the intermediates of the high-temperature Goldberg reactions. Reaction of complexes 2 and 3 with aryl halides generates the N-arylation products 5-8, accompanied by the formation of a copper(I) complex Cu(dppf)X (X = I or Br) 4, which has been determined by LC-MS analysis. These results provide new evidence for the mechanism of copper(I)-catalyzed Goldberg reaction.

A simple, efficient, and non-metal-catalyzed synthetic method for allyl-epoxides and diallyl-epoxides by allylation of α-haloketones and esters with allylmagnesium bromide in mild conditions is reported in this article. It inherited some advantages of the organomagnesium reagents such as availability, operational simplicity and low toxicity., (This journal is © The Royal Society of Chemistry 2012)

Carbonyl compounds react with organozinc reagents in the presence of diphenyl phosphite to give the corresponding olefins. A variety of 1,3-dienes and unsaturated esters were obtained in moderate to excellent yields under mild conditions., (This journal is © The Royal Society of Chemistry 2012)

A simple, efficient, and non-metal catalyzed synthetic method for the preparation of substituted allyl- and propargyl-epoxides by allylation and propargylation of α-halo ketones with organozinc reagents in mild conditions is reported in this paper. The present method complements the existing synthetic methods due to some advantageous properties of the organozinc reagents such as availability, selectivity, operational simplicity and low toxicity.

The widely available carbonyl compounds react with Grignard reagents in the presence of diethyl phosphite to give the corresponding olefins in good to excellent yields: A range of conjugated dienes, terminal olefins, multisubstituted-alkenes and conjugated enynes could be readily obtained by the method in mild conditions.