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Coordination polymers are a sub-class of coordination complexes that possess unique opto-electronic properties and hence can be utilized for a wide range of applications such as sensing and photocatalysis. Herein, four new coordination polymers (CPs) with formula [Mn2(HL)(NMP)(H2O)2]n (1), [Mn2(HL)(DMA)2(H2O)·2DMA]n (2), [Mn(H3L)(H2O)2]n (3) and [Mn(H3L)(H2O)(4,4′-bipy)]n (4) (H5L = 3,5-bis(3,4-dicarboxyphenoxy) benzoic acid and NMP = N-methyl pyrrolidone) were synthesized under hydrothermal conditions and characterized. The single-crystal X-ray analysis revealed a distorted octahedral geometry around Mn(II) in these CPs and that they form an extended hydrogen bonding and π⋯π stacking interaction-assisted network. Thermogravimetric studies revealed that the CPs, 1, 2, 3 and 4, have variable thermal stability in the range of 82–194 °C. All four complexes exhibited optical semiconducting behavior and hence were used as photocatalysts for the photodecomposition of antibiotics, including chloramphenicol (CAP), nitrofurazone (NFZ), ornidazole (ODZ), oxytetracycline (OXY) and sulfamethoxazole (SMT). Among the CPs, CP 2 exhibited an impressive 91.93% degradation of NFZ within 60 min. The plausible photocatalytic mechanism was explained with the assistance of Hirshfeld surface analysis. [ABSTRACT FROM AUTHOR]

Cathodic photoelectrochemistry with superior photostability and anti-interference capability has been shown to be appealing in the field of bioanalysis. However, a major challenge regarding this technology is the limited photoinduced electron transfer signal transduction mechanism. Herein, we disclose a finding of the bioinduced surface oxygen vacancy (VO) on bismuth trioxide (Bi2O3) nanocrystals, which underlies an innovative mechanism for cathodic photoelectrochemical (PEC) bioanalysis. The protocatechuic acid engendered from the tandem enzymatic reaction of p-hydroxybenzoate hydroxylase (PHBH) and glucose-6-phosphate dehydrogenase (G6PD) can coordinate with the surface of Bi2O3 nanocrystals through forming binary Bi–O–C bonds, which breaks the initial Bi–O bonds and enables the escape of O2– from the lattice to form surface VOin situ. The surface VO can function as a separation center for charge carriers, which is favorable to the generation of cathodic photocurrent. In such a system, the cathodic signal is linearly correlated with the targets, glucose-6-phosphate (G-6-P) and G6PD, in concentration ranges of 8.0 to 8.0 × 105 μM and 0.1 to 1.0 × 104 U/L, achieving detection limits of 2.0 μM and 0.03 U/L, respectively. This study not only offers a way of introducing surface VOin situ but also enriches the current toolbox of cathodic PEC bioassays and promises to stimulate further interest in exploring surface effect engineering in other fields. [ABSTRACT FROM AUTHOR]

A Na(I) complex, [Na(4,4’-bipyridine)2·(H2O)4]·L·OH·2H2O (L = 2-formyl-benzenesulfonate-hydrazine), has been synthesized. And its structure was determined by X-ray single crystal diffraction analysis. The Na(I) complex belongs to orthorhombic, space group C2221 with a = 7.9162(16) Å, b = 18.451(4) Å, c = 26.397(5) Å, V= 3855.7(13) Å3, Z = 4, Dc = 1.394 mg·m-3, μ = 0.218 mm-1, F(000) =1689, and final R1 = 0.0683, ωR2 = 0.2017. The result shows that the Na(I) center is six-coordination with a N2O4 distorted octahedral coordination environment. The Na(I) complex forms 1D chain structure by the π-π stacking interaction.

The development of efficient methods for the detection of T4 DNA ligase is extremely important for public health. The present work demonstrates the integration of engineerable oxidase nanozyme of LaMnO3.26 nanomaterials for the colorimetric detection of T4 DNA ligase. Specifically, the LaMnO3.26 nanomaterials exhibited oxidase-like activity, oxidizing o-phenylenediamine (OPD), 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), and 3,3′,5,5′-tetramethylbenzidine (TMB) to their corresponding oxidation products, which featured maximum absorption wavelengths at 450, 417 and 650 nm, respectively, while pyrophosphate ion (PPi) caused an obvious decrease in the oxidase-like activity of LaMnO3.26 through its surface coordination with the surface-exposed Mn element and induced aggregation of the nanozyme. Attributed to the PPi regulated oxidase nanozyme activity, LaMnO3.26 served as a colorimetric probe for the quantitative detection of T4 DNA ligase assisted by a hyperbranched amplification reaction for signal amplification. The T4 DNA ligase was detected with a linear range of 4.8 × 10−3 to 6.0 U mL−1, achieving a detection limit of 1.6 × 10−3 U mL−1. The outcome indicated that the developed nanozyme might be extended to a broad range of practical applications. [ABSTRACT FROM AUTHOR]