Layered assembly of PEGylated graphene oxide and Mg-Al layered double hydroxide nanosheets with superior adsorption capacity and selective isolation of hemoglobin.

This study developed a novel organic-inorganic hybrid composite, shortly as GO-PEG-LDHs, by self-assembly of exfoliated Mg-Al layer double hydroxide (LDHs) on the polyethylene glycol (PEG) grafted graphene oxide (GO) to achieve the selective adsorption of hemoglobin (Hb). The prepared GO-PEG-LDHs has a hierarchical structure with a homogeneous loading of exfoliated LDHs nano-sheets on its surface. The adsorption test reveals that GO-PEG-LDHs exhibits an adsorption efficiency of 95.03% for Hb and 3.45% for bovine serum albumin (BSA). The adsorption of Hb follows the Langmuir model, with an ultrahigh adsorption capacity of 55248.6 mg/g, which is higher than any previously reported materials. Meanwhile, the adsorbed Hb can be efficiently recovered through elution with a 50 mM Tris-HCl buffer, with an elution efficiency of 80.77%. Circular dichroism (CD) spectra indicate no conformational change for Hb during the process of adsorption/desorption. Furthermore, the composite demonstrates the ability to selectively isolate Hb in the presence of interfering protein BSA, indicating its potential for practical applications.

Chitosan-Se Engineered Nanomaterial Mitigates Salt Stress in Plants by Scavenging Reactive Oxygen Species.

Soil salinity seriously hinders the sustainable development of green agriculture. The emergence of engineered nanomaterials has revolutionized agricultural research, providing a new means to overcome the limitations associated with current abiotic stress management and achieve highly productive agriculture. Herein, we synthesized a brand-new engineered nanomaterial (Cs-Se NMs) through the Schiff base reaction of oxidized chitosan with selenocystamine hydrochloride to alleviate salt stress in plants. After the addition of 300 mg/L Cs-Se NMs, the activity of superoxide dismutase, catalase, and peroxidase in rice shoots increased to 3.19, 1.79, and 1.85 times those observed in the NaCl group, respectively. Meanwhile, the MDA levels decreased by 63.9%. Notably, Cs-Se NMs also raised the transcription of genes correlated with the oxidative stress response and MAPK signaling in the transcriptomic analysis. In addition, Cs-Se NMs augmented the abundance and variety of rhizobacteria and remodeled the microbial community structure. These results provide insights into applying engineered nanomaterials in sustainable agriculture.

Smart G-quadruplex hydrogels: From preparations to comprehensive applications.

In recent years, the accelerated development of G-quadruplexes and hydrogels has driven the development of intelligent biomaterials. Based on the excellent biocompatibility and special biological functions of G-quadruplexes, and the hydrophilicity, high-water retention, high water content, flexibility and excellent biodegradability of hydrogels, G-quadruplex hydrogels are widely used in various fields by combining the dual advantages of G-quadruplexes and hydrogels. Here, we provide a systematic and comprehensive classification of G-quadruplex hydrogels in terms of preparation strategies and applications. This paper reveals how G-quadruplex hydrogels skillfully utilize the special biological functions of G-quadruplexes and the skeleton structure of hydrogels, and expounds its applications in the fields of biomedicine, biocatalysis, biosensing and biomaterials. In addition, we deeply analyze the challenges in preparation, applications, stability and safety of G-quadruplex hydrogels, as well as potential future development directions.

A functional cobalt-organic framework constructed by triphenylamine tricarboxylate: Detect nitroaromatics by fluorescence sensing and UV-shielding.

Luminescent metal-organic frameworks (LMOF) with ligand-modified are a promising strategy to be applied to fabricate chemical sensors. Herein, a novel Co (II) metal-organic framework (Co-MOF), namely Co [(NTB) bpy] (NTB = 4,4'4″-tricarboxylic acid triphenylamine, bpy = 4,4 '-bipyridyl), was successfully synthesized with excellent water stability and fluorescence properties. Due to the propeller structure of NTB ligands, a special topological structure of Co-MOF was shown: {24.416.68}{2}4. It was proved that Co-MOF has great stability by soaking in different solvents for two weeks. Remarkably, the fluorescence quenching experiment verified that Co-MOF has excellent fluorescence sensor performance. Trinitrophenol, 2,4-dinitrophenol, and 2-amino-4-nitrotoluene (10-5 M) with LOD of 9.00 × 10-5, 5.40 × 10-5 and 5.07 × 10-6 M can be detected via the process of fluorescence enhancement and quenching. Throughout the investigation, the mechanics of fluorescence quenching was performed. Due to the excellent UV absorption capacity of Co-MOF, it was a promising application to combine low-dimensional nanomaterials with sustainable biomass materials. A hybrid films of Co-MOF and cellulose acetate (CA) was generated. The hybrid films had highly transparency in the visible wavelength range and excellent UV-shielding ability owing to the CA/Co-MOF hybrid films enhanced the UV absorption capacity of Co-MOF.

A Displacement Sensing Method Based on Permanent Magnet and Magnetic Flux Measurement.

This paper proposes a displacement sensing method based on magnetic flux measurement. A bridge-structured magnetic circuit, formed by permanent magnets and two ferromagnetic cores, is designed and discussed. The analyses of the equivalent magnetic circuit and three-dimensional finite element simulations showed that the magnetic flux density changes linearly with the reciprocal of the sum of a constant and the displacement. A prototype sensor of the bridge structure is developed that consists of four permanent magnets as excitation, a Hall sensor as reception, and two ferromagnetic cores as the connection. Experiments have validated the feasibility of this method. The measured results show a good linearity between the sensor's output and the reciprocal of the sum of a constant and the displacement, with a correlation coefficient greater than 0.9995 across different measurement ranges. Additionally, the measured results significantly indicate that the proposed sensor is compatible with different ferromagnetic materials with a worst-case error of less than 5%. The proposed sensor has the advantages of low cost and good linearity; however, the test object is limited to ferromagnetic materials.

Dispersion of Multi-Walled Carbon Nanotubes by Polymers with Carbazole Pendants.

For various applications, it is essential to enhance the colloidal stabilization of carbon nanotube (CNT) dispersions. Here, the polymers with carbazole pendants of poly(4-(N-carbazolyl)methylstyrene-bl-poly(ethylene glycol) methyl ether methacrylate) (PCMS5-b-PAPEG73 and PCMS16-b-PAPEG43) and PCMS30, synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization, were used for noncovalent functionalization of multiwalled carbon nanotubes (MWCNTs) in tetrahydrofuran (THF), offering efficient colloidal stabilization. Meanwhile, the adsorption of polymers onto MWCNTs was investigated. The results showed that the MWCNTs decorated with these three polymers in THF exhibited different colloidal stabilization and adsorption capacity. Moreover, the MWCNT dispersions could be stabilized for days and their colloidal stabilization elevated with the increase of polymer concentrations. The block copolymer PCMS16-b-PAPEG43 exhibited the optimal adsorption and dispersion capability for MWCNTs. These findings imply that PCMSm-b-PAPEGn will be a desirable dispersant for optimizing the stabilization of CNT dispersion, making carbon nanotubes (CNTs) achievable in different applications.