Electrochemical Signal Enhancer Fabricated Using Lysine‐rich Peptide for Ultrasensitive Electrochemical DNA Biosensor Analysis

Here we present a novel design of electrochemical signal enhancer to increase the detection sensitivity of electrochemical DNA biosensors. The key element of this enhancer is a lysine‐rich peptide (LRP). Its C‐terminal is conjugated with a planer molecule, being able to intercalate into the base pairs of probe‐target duplexes. The lysine residues of LRP are covalently linked with electrochemical signal indicators, acting as an assembly of electrochemical signal indicators. Experimental results proved the feasibility of the novel design. We have examined the effects of the numbers of lysine residues and the hybridization conditions on the detection sensitivity. The optimization procedures have led to significant sensitivity enhancement, and the LOD (limit of detection) has been determined to be 1.4 amol. This enhancer demonstrates advantages of easy operation, simple instrumentation, and high exemption from environmental influence.     

A [001]-Oriented Hittorf's Phosphorus Nanorods/Polymeric Carbon Nitride Heterostructure for Boosting Wide-Spectrum-Responsive Photocatalytic Hydrogen Evolution from Pure Water

Red phosphorus is a promising photocatalyst with wide visible-light absorption up to 700 nm, but the fast charge recombination limits its photocatalytic hydrogen evolution reaction (HER) activity. Now, [001]-oriented Hittorf's phosphorus (HP) nanorods were successfully grown on polymeric carbon nitride (PCN) by a chemical vapor deposition strategy. Compared with the bare PCN and HP, the optimized PCN@HP hybrid exhibited a significantly enhanced photocatalytic activity, with HER rates reaching 33.2 and 17.5 μmol h⁻¹ from pure water under simulated solar light and visible light irradiation, respectively. It was theoretically and experimentally indicated that the strong electronic coupling between PCN and [001]-oriented HP nanorods gave rise to the enhanced visible light absorption and the greatly accelerated photoinduced electron–hole separation and transfer, which benefited the photocatalytic HER performance.     

A fast iterative method to find the matrix geometric mean of two HPD matrices

The purpose of this research is to present a novel scheme based on a quick iterative scheme for calculating the matrix geometric mean of two Hermitian positive definite (HPD) matrices. To do this, an iterative scheme with global convergence is constructed for the sign function using a novel three‐step root‐solver. It is proved that the new scheme is convergent and shown to have global convergence behavior for this target, when square matrices having no pure imaginary eigenvalues. Next, the constructed scheme is used and extended through a well‐known identity for the calculation of the matrix geometric mean of two HPD matrices. Ultimately, several experiments are collected to show its usefulness.     

Preparation and in vivo imaging of a novel potential αvβ3 targeting PET/MRI dual-modal imaging agent

Journal of Radioanalytical and Nuclear Chemistry - Multi-modal biomedical imaging has played an essential role in tumor diagnosis. However, constructing a multi-modal imaging contrast agent with...     

A Class of Quasilinear Schrödinger Equations with Improved (AR) Condition

By improving the classical (AR) condition, we establish the existence of positive solutions for a class of quasilinear Schrödinger equations.

     

PDα‐type distributed learning control for nonlinear fractional‐order multiagent systems

This paper considers the consensus tacking problem for nonlinear fractional‐order multiagent systems by presenting a PD^α‐type iterative learning control update law with initial learning mechanisms. The asymptotical convergence of the proposed distributed learning algorithm is strictly proved by using the properties of fractional calculus. A sufficient condition is derived to guarantee the whole multiagent system achieving an asymptotic output consensus. An illustrative example is given to verify the theoretical results.     

Copper-Catalyzed Trifunctionalization of Alkynes: Rapid Formation of Oxindoles Bearing Geminal Diboronates

A copper-catalyzed trifunctionalization of alkynes that provides rapid access to oxindoles bearing a geminal diboronate side chain, highlighted by the simultaneous formation of one C−C bond and two C−B bonds, is reported. This new reaction features simple reaction conditions (ligand-free catalysis), a general substrate scope, and excellent chemoselectivity. Mechanistic study revealed a reaction sequence constituted by, in the order, borylation, intramolecular cross-coupling, hydroboration, which has been rarely documented.     

Molecular Acceptors Based on a Triarylborane Core Unit for Organic Solar Cells

Triarylboranes that exhibit p–π* conjugation serve as versatile building blocks to design n-type organic/polymer semiconductors. A series of new molecular acceptors based on triarylborane is reported here. These molecules are designed with a boron atom that bears a bulky 2,4,6-tri-tert-butylphenyl (Mes*) substituent at the core and strong electron-withdrawing 2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile (IC) units as the end-capping groups that are linked to the core by bithiophene bridges. Butyl or butoxy groups are introduced to the bithiophene units to tune the optoelectronic properties. These molecules show nearly planar backbones with highly localized steric hindrance at the core, low LUMO/HOMO energy levels, and broad absorption bands spanning the visible region, which are all very desirable characteristics for use as electron acceptors in organic solar cell (OSC) applications. The attachment of butyl groups to the bithiophene bridges brings about a slightly twisted backbone, which in turn promotes good solubility and homogeneous donor/acceptor blend morphology, whereas the introduction of butoxy groups leads to improved planarity, favorable stacking in the film state, and a greatly reduced band gap. OSC devices based on these molecules exhibit encouraging photovoltaic performances with power conversion efficiencies reaching up to 4.07 %. These results further substantiate the strong potential of triarylboranes as the core unit of small molecule acceptors for OSC applications.     

Effects of intramolecular hydrogen bonds on phosphorescence emission: A theoretical perspective

Importing intramolecular hydrogen bond in phosphorescent transition metal complexes has been considered one of the excellent approaches to improve the electroluminescence performance of organic light-emitting diodes in real applications. However, the relationships between such H-bond structure and phosphorescent properties have not been theoretically revealed yet. In this study, two types of intramolecular hydrogen bonds are introduced into the two classes of traditional materials, that is, Pt(II) and Ir(III) complexes ( 1a and 2a ) to completely elucidate their influence on the structures and properties by comparing with the original phosphors ( 1b and 2b ) using density functional theory/time-dependent density functional theory for the first time. A comprehensive analysis of the geometric structures, molecular orbitals, and luminescence properties (including phosphorescence emission wavelengths and radiative and nonradiative decay processes) has been carried out. Our theoretical model highlights that complexes 1a and 2a embedded with H-bonds significantly promote the phosphorescence emission band blue-shifted and restrict molecular deformations compared with the corresponding 1b and 2b , which can provide helpful guidance to regulate and design several aspects of highly efficient blue phosphorescent emitters.