A Zr-based metal-organic framework with zinc tetrakis(carboxyphenyl)-porphyrin (ZnTCPP) groups (MOF-525-Zn) was utilized to develop a novel electrochemiluminescence (ECL) biosensor for highly sensitive protein kinase activity assay. In this work, in terms of ECL measurements and cyclic voltammetry, the cathodic ECL behaviors of MOF-525-Zn in aqueous media were thoroughly investigated for the first time. The photoelectric active groups ZnTCPP on the MOF-525-Zn frameworks could promote the generation of singlet oxygen ((1)O2) via a series of electrochemical and chemical reactions, resulting in a strong and stable red irradiation at 634 nm. Additionally, the surfactant tetraoctylammonium bromide (TOAB) further facilitated dissolved oxygen to interact with the active sites ZnTCPP of MOF-525-Zn. Furthermore, the inorganic Zr-O clusters of MOF-525-Zn were simultaneously served as the recognition sites of phosphate groups. And then, an ultrasensitive ECL sensor was proposed for protein kinase A (PKA) activity detection with a linear range from 0.01 to 20 U mL(-1) and a sensitive detection limit of 0.005 U mL(-1). This biosensor can also be applied for quantitative kinase inhibitor screening. Finally, it exhibits good performance with high stability and acceptable fabrication reproducibility, which provide a valuable strategy for clinic diagnostics and therapeutics.

We report an organic lamellar single crystal as a versatile optoelectronic material in optical pumping and light-emitting transistors. The styrene derivative crystals with intrinsically ordered stacking structures, low impurities, and high photoluminescence efficiency offer a low threshold energy of 21 μJ cm −2 for amplified spontaneous emission and extraordinary device performance in terms of a striking external quantum efficiency of 3.63%, far exceeding the benchmark value in this field.

<div>The acoustic volume measuring method is a promising non-contact method for volume determination of mass weights. To improve the measuring accuracy of volume determination with the non-contact acoustic method, an acoustic measuring system with two measuring chambers is newly designed to compensate for the non-linearity measuring errors. When reducing the remaining air in the measuring chamber, the measuring accuracy can be greatly reduced. The volumes of mass standards ranging from 100 g to 5 kg are tested to evaluate the non-linearity errors of the volume measurement. The relative uncertainties of the acoustic volume determination are below 7.0 ×10^-4 (<em>k</em>=2).</div>

We report the preparation of two high-quality lamellar crystals of cayno-substituted p-phenylene vinylene derivatives and the fabrication of their transistors. The transistors were demonstrated hysteresis-free, low subthreshold swing of 0.10...

Magnetic interactions may lead to errors in precision mass metrology. There are two factors named magnetic susceptibility and magnetic polarization which need to be determined before mass metrology. First four methods are compared and analyzed suitable range, requirement, uncertainty and note in comparison process. Then uncertainty factors are given out, and description of differences between normal weights and micro-gram standards are presented in the paper. It is easy to become magnetized if the weight is not well protected in manufacture or daily using. So it is important to control its safe and perform periodic self-verification on it.