2D Perovskites for Biological Sensors

2D perovskite’s quantum confinement and superlattices enhance electron and hole recombination which maximizes the photoluminescence quantum efficiency for optical devices. However, only a few works have been reported for biological applications, especially, DNA associated. Contemporary gene-editing science through CRISPR technology is advantageous as all types of nucleic acid chains such as RNA, single-stranded DNA, and double-stranded DNA can be modified. There are numerous reports that base pairs of nucleic acids are nonpolar and 2D perovskites that are capped with aliphatic chains possibly can operate as an optical sensor for detecting a specific sequence of DNA. Here, we demonstrate organic-inorganic halide 2D perovskite’s – capped with eight carbon long aliphatic chains – optical and structural properties. Self-assembly of tin-based perovskites showed near-unity photoluminescence quantum yield but had poor stability in water or ambient condition due to hydrolysis whereas lead-based perovskites showed less PL but were stable in water at high concentration. 2D perovskites’ unique multiple emission peaks at different wavelengths, water stability, and intensity discrepancy when conjugated in nucleoside dispersed solution were studied. However, complex multiple directionalities of PL emission, water stability by concentration, minor PL intensity or wavelength discrepancy, and toxicity followed by the lead source for the perovskites are conflicting with robust and convenient detection technique for the DNA.

Characterization of Soil Organic Matter Individual Fractions (Fulvic Acids, Humic Acids, and Humins) by Spectroscopic and Electrochemical Techniques in Agricultural Soils

The objective of this paper was to investigate the molecular characterization of soil organic matter fractions (humic substances (HS): fulvic acids-FAs, humic acids-HAs, and humins-HNs), which are the most reactive soil components. A wide spectrum of spectroscopic (UV–VIS and VIS–nearIR), as well as electrochemical (zeta potential, particle size diameter, and polydispersity index), methods were applied to find the relevant differences in the behavior, formation, composition, and sorption properties of HS fractions derived from various soils. Soil material (n = 30) used for the study were sampled from the surface layer (0–30 cm) of agricultural soils. FAs and HAs were isolated by sequential extraction in alkaline and acidic solutions, according to the International Humic Substances Society method, while HNs was determined in the soil residue (after FAs and HAs extraction) by mineral fraction digestion using a 0.1M HCL/0.3M HF mixture and DMSO. Our study showed that significant differences in the molecular structures of FAs, Has, and HNs occurred. Optical analysis confirmed the lower molecular weight of FAs with high amount of lignin-like compounds and the higher weighted aliphatic–aromatic structure of HAs. The HNs were characterized by a very pronounced and strong condensed structure associated with the highest molecular weight. HAs and HNs molecules exhibited an abundance of acidic, phenolic, and amine functional groups at the aromatic ring and aliphatic chains, while FAs mainly showed the presence of methyl, methylene, ethenyl, and carboxyl reactive groups. HS was characterized by high polydispersity related with their structure. FAs were characterized by ellipsoidal shape as being associated to the long aliphatic chains, while HAs and HNs revealed a smaller particle diameter and a more spherical shape caused by the higher intermolecular forcing between the particles. The observed trends directly indicate that individual HS fractions differ in behavior, formation, composition, and sorption properties, which reflects their binding potential to other molecules depending on soil properties resulting from their type. The determined properties of individual HS fractions are presented as averaged characteristics over the examined soils with different physico-chemical properties.

Structural characterization of soil organic matter individual fractions (fulvic acids, humic acids and humins) in relation to potential sorption of organic contaminants

<p>The objective of this paper was to investigate the molecular characterization of individual humic substances ( fulvic acids-FAs, humic ascids-HAs, and humins-HNs), which are the most reactive soil components and exhibit high sorption capacity in relation to various groups of organic contaminants. A wide spectrum of spectroscopic (UV-VIS, VIS-nearIR), as well as electrochemical (zeta potential, particle size diameter, polidyspersity index), methods were applied to find the relevant differences in the behavior, formation, composition and sorption properties of HS fractions derived from various mineral soils.</p><p>Soil material (n = 30) used for the study were sampled from the surface layer (0–30 cm) of agricultural soils. FAs and HAs were isolated by sequential extraction in alkaline and acidic solutions, according to the International Humic Substances Society method, while HNs was determined in the soil residue (after FAs and HAs extraction) by mineral fraction digestion using a 0.1M HCL/0.3M HF mixture and DMSO.</p><p>Our study showed that significant differences in the molecular structures of FAs, HAs and HNs occurred. Optical analysis confirmed the lower molecular weight of FAs with high amount of lignin-like compounds and the higher weighted aliphatic–aromatic structure of HAs. The HNs were characterized by a very pronounced and strong condensed structure associated with the highest molecular weight. HAs and HNs molecules exhibited an abundance of acidic, phenolic and amine functional groups at the aromatic ring and aliphatic chains, while FAs mainly showed the presence of methyl, methylene, ethenyl and carboxyl reactive groups. HS was characterized by high polydispersity related with their structure. FAs were characterized by ellipsoidal shape as being associated to the long aliphatic chains, while HAs and HNs revealed a smaller particle diameter and a more spherical shape caused by the higher intermolecular forcing between the particles.  </p><p>The observed trends directly indicate that individual HS fractions differ in behavior, formation, composition and sorption properties, which reflects their binding potential to different group of organic contaminants, but the general properties of individual fractions are similar and do not depend on the type of soil.</p><p><em>Acknowledgement: The studies were supported from the National Science Centre project No. 2018/29/N/ST10/01320 “Analysis of the fractional composition and sorption properties of humic substances in relation to various groups of organic contaminants”</em></p>

Supramolecular Assemblies of Dipyrrolyldiketone CuII Complexes

Dipyrrolyldiketones are essential building units of anion-responsive π-electronic molecules and ion-pairing assemblies. Here, we demonstrated that they form complexes with CuII characterized by planar geometries. The solid-state stacking assembled structures, as revealed by single-crystal X-ray analysis, were modulated by the substitution of pyrrole units. The rectangular shapes of the CuII complexes resulted in the formation of mesophases upon introduction of aliphatic chains.

New iron(II) spin-crossover metallomesogen with terminal C=C bond long aliphatic chains

Spin-crossover (SCO) molecules have been proposed for applications in molecular spintronics devices due to their bistability which can be reversibly switched by external stimulus. Here, we report the synthesis, structure...

Boron-containing capsaicinoids

This study reports on the preparation of eight new boron-containing capsaicinoids bearing long aliphatic chains, and initial bioactivities are reported.

meso-Free dipyrrins: Formation of assembled structures including a 2D ordered pattern

Fairly planar meso-unsubstituted dipyrrins, some of which had trialkoxyphenyl moieties, were synthesized. They underwent self-assembly in less polar solvents and the derivative bearing aliphatic chains exhibited a 2D ordered pattern at the solid/liquid interface, as observed through scanning tunneling microscopy.