In-Depth Study on the Effects of Impurity Ions in Saline Wastewater Electrolysis.

Concentration followed by electrolysis is one of the most promising ways for saline wastewater treatment, since it could produce H2, Cl2, and an alkaline solution with deacidification potential. However, due to the diversity and difference of wastewater, knowledge on the suitable salt concentration for wastewater electrolysis and the effects of mixed ions are still lacking. In this work, electrolysis experiments of mixed saline water were conducted. The salt concentration for stable dechlorination was explored, with in-depth discussions on the effects of typical ions such as K+, Ca2+, Mg2+, and SO42-. Results showed that K+ had a positive effect on the H2/Cl2 production of saline wastewater through accelerating the mass transfer efficiency in the electrolyte. However, the existence of Ca2+ and Mg2+ had negative effects on the electrolysis performance by forming precipitates, which would adhere to the membrane, reduce the membrane permeability, occupy the active sites on the cathode surface, and also increase the transport resistance of the electrons in the electrolyte. Compared to Mg2+, the damaging effect of Ca2+ on the membrane was even worse. Additionally, the existence of SO42- reduced the current density of the salt solution by affecting the anodic reaction while having less of an effect on the membrane. Overall, Ca2+ ≤ 0.01 mol/L, Mg2+ ≤ 0.1 mol/L and SO42- ≤ 0.01 mol/L were allowable to ensure the continuous and stable dechlorination electrolysis of saline wastewater.

Application of Janus Particles in Point-of-Care Testing.

Janus particles (JPs), named after the two-faced Roman god, are asymmetric particles with different chemical properties or polarities. JPs have been widely used in the biomedical field in recent years, including as drug carriers for targeted controlled drug release and as biosensors for biological imaging and biomarker detection, which is crucial in the early detection and treatment of diseases. In this review, we highlight the most recent advancements made with regard to Janus particles in point-of-care testing (POCT). Firstly, we introduce several commonly used methods for preparing Janus particles. Secondly, we present biomarker detection using JPs based on various detection methods to achieve the goal of POCT. Finally, we discuss the challenges and opportunities for developing Janus particles in POCT. This review will facilitate the development of POCT biosensing devices based on the unique properties of Janus particles.

Development of boronic acid-functionalized mesoporous silica-coated core/shell magnetic microspheres with large pores for endotoxin removal.

Endotoxins are found almost everywhere and possess high toxicity in vivo and in vitro. Here we design a novel boronate affinity material, called boronic acid-functionalized mesoporous silica-coated core/shell magnetic microspheres (Fe3O4@nSiO2@mSiO2-BA) with large pores (pore size > 20 nm) based on the chemical structure and physical properties of endotoxins, for facile and highly efficient removal of endotoxins. Dual modes for endotoxin removal were proposed and confirmed in this work: the endotoxin aggregates with size < 20 nm were bound with boronic acid ligands chemically modified on the inner and outer surface of the large pores of Fe3O4@nSiO2@mSiO2-BA microspheres; while the larger endotoxin micelles (size >20 nm) were absorbed on the outer surface of the prepared material based on boronate affinity. Transmission electron microscopy (TEM), X-ray diffraction (XRD), nitrogen adsorption/desorption isotherms and Fourier transform infrared (FT-IR) spectroscopy confirm that Fe3O4@nSiO2@mSiO2-BA microspheres possess core/shell structure, uniform diameter (520 nm), high surface area (205.57 m2/g), large mesopores (21.8 nm) and boronic acid ligands. The purification procedures of Fe3O4@nSiO2@mSiO2-BA microspheres for endotoxin were optimized, and 50 mM NH4HCO3 (pH 8.0) and 0.05 M fructose were selected as loading/washing, elution buffers, respectively. The binding capacity of Fe3O4@nSiO2@mSiO2-BA microspheres for endotoxin was calculated to be 60.84 EU/g under the optimized conditions. Finally, the established analytical method was applied to remove endotoxins from plasmid DNA. After endotoxin removal, the endotoxin content in plasmid DNA was reduced from 0.0026 to 0.0006 EU/mL for two-fold concentration, and from 0.0088 to 0.0022 EU/mL for five-fold concentration after binding, respectively. Additional advantages of the prepared boronate affinity material include excellent stability, reusability/repeatability, and low cost. Boronate affinity materials with large pores could thus prove to be powerful adsorbents for endotoxin removal and the potential applications in the aspects of biological research, pharmaceutical industry, and life health.

A multifunctional ternary Cu(II)-carboxylate coordination polymeric nanocomplex for cancer thermochemotherapy.

Metal-based photothermal therapy has been widely used in the biomedicine field and includes gold nanoparticles, silver nanoparticles and copper sulfide nanoparticles. Furthermore, the coordination bonding-based metal nanocomplex is a new generation of photothermal agents for cancer therapy due to its high photothermal transduction efficiency, good biocompatibility, biodegradation and bioactivity. In this study, we designed a coordination bonding-based copper (Cu(II))-carboxylate ternary architecture, which consists of a conjugate dopamine-modified nontoxic hyaluronic acid, copper ions and citric acid. When the Cu(II) coordinated with the carboxyl groups, the splitting d orbitals energy gap of Cu(II) and the capability of electron transition were enhanced, which can increase the extinction ability in the near-infrared region for enhancing photothermal therapy. Moreover, the degradation of hyaluronic acid by hyaluronidase highly expressed in the tumor microenvironment led to the release of Cu-citric acid complexes, thus exhibiting an additional chemotherapeutic effect. The nanocomplexes possessed high-performance photothermal conversion, determined to be 21.3%. The solution could be easily heated to above 42 °C, which was sufficient to ablate the cancer cells. An obvious decrease in cell viability was observed in B16F10 cells incubated with the nanocomplexes under laser at the lower concentration of 20 µg/mL Cu(II). Upon near-infrared laser irradiation, the nanocomplexes showed high photothermal therapy and chemotherapeutic efficacy for breast cancer in vivo. This study demonstrated that the Cu(II)-carboxylate coordination nanocomplex is a promising new effective and facilely prepared thermochemotherapy agent for combination therapy against cancer.

Highly Efficient Solid-Phase Labeling of Saccharides within Boronic Acid Functionalized Mesoporous Silica Nanoparticles.

Labeling is critical for the detection, quantitation, and structural identification of saccharides. However, conventional liquid-phase labeling suffers from apparent disadvantages, such as time-consuming, the presence of excessive labeling reagent, and high applicable saccharide concentration. A solid-phase approach is presented for highly efficient labeling of saccharides, using boronic acid functionalized mesoporous silica nanoparticles (MSNs) as a selective extraction sorbent and nanoscale reactor. The solid-phase labeling approach exhibited several significant advantages, including: much faster reaction speed (taking only 2 min), high product purity, and much lower applicable saccharide concentration (four orders of magnitude lower than that of liquid-phase labeling). Thus, this labeling approach opens up new avenues to the facile and efficient labeling of saccharides.

Zirconium arsenate-modified silica nanoparticles for specific capture of phosphopeptides and direct analysis by matrix-assisted laser desorption/ionization mass spectrometry.

In this paper, we report, as far as we are aware, the first use of zirconium arsenate-modified silica nanoparticles (ZrAs-SNPs) for specific capture of phosphopeptides, followed by matrix-assisted laser desorption/ionization mass spectrometric (MALDI MS) analysis. Under the optimized enrichment conditions, the efficiency and specificity of ZrAs-SNPs were evaluated with tryptic digests of four standard proteins (α-casein, ß-casein, ovalbumin, and bovine serum albumin) and compared with those of titanium arsenate-modified silica nanoparticles (TiAs-SNPs). The results showed that more selective enrichment of multiply phosphorylated peptides was observed with ZrAs-SNPs than with TiAs-SNPs whereas TiAs-SNPs resulted in slightly better recovery of singly phosphorylated peptides. ZrAs-SNPs were chosen for direct capture of phosphopeptides from diluted human serum of healthy and adenocarcinoma individuals. Our experimental profiling of serum phosphopeptides revealed that the level of phosphorylated fibrinogen peptide A was up-regulated in the serum of adenocarcinoma patients in comparison with healthy adults. This suggests the possibility of using ZrAs-SNPs for discovery of biomarkers of the pathogenesis process of tumors.

Simple and rapid determination of thiol compounds by HPLC and fluorescence detection with 1,3,5,7-tetramethyl-8-phenyl-(2-maleimide) difluoroboradiaza-s-indacene.

A rapid and simple background-free high-performance liquid chromatographic (HPLC) approach has been developed for simultaneously determining free thiol compounds including coenzyme A (CoA), cysteine (Cys), glutathione (GSH) and N-acetyl-cysteine (NAC) in biological samples by using 1,3,5,7-tetramethyl-8-phenyl-(2-maleimide) difluoroboradiaza-s-indacene (TMPAB-o-M) as fluorogenic reagent. After derivatization under physiological conditions within 6 min, baseline separation was finished in just 6 min using isocratic elution with reversed-phase HPLC and fluorescence detection. Excellent linearity was observed for all analytes over their concentration ranges of 1-500 nM and detection limits ranging 0.13 nM for CoA to 0.25 nM for Cys (S/N=3) were achieved. The utility of the proposed method has been validated by measuring thiol compounds mentioned above in tissue, fluid and cell samples. The results indicated that this approach was well suited for high-throughput quantitative determination of thiols and study of the physiological role of them.

Isolation of phosphopeptides using zirconium-chlorophosphonazo chelate-modified silica nanoparticles.

Due to the low abundance of phosphoproteins and substoichiometry of phosphorylation, the elucidation of protein phosphorylation requires highly specific materials for isolation of phosphopeptides from biological samples prior to mass spectrometric analysis. In this study, chlorophosphonazo type derivatives of chromotropic acid including p-hydroxychlorophosphonazo (HCPA) and chlorophosphonazo I (CPA I), traditionally used in the photometric determination of transition metal ions, have been employed as chelating ligands in the preparation of novel affinity materials for phosphopeptide enrichment. The chromogenic reagents of HCPA and CPA I were chemically modified on the surface of silica nanoparticles, and the functionalized materials were charged with zirconium ions through the strong complexation between chelating ligands and Zr(4+). The obtained zirconium-chlorophosphonazo chelate-modified silica nanoparticles (Zr-HCPA-SNPs and Zr-CPA I-SNPs) were applied to the selective enrichment of phosphopeptides, followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis. The purification procedures were optimized using α-casein digest at first, and then the performance of these two affinity materials for efficient and specific enrichment of phosphopeptides was evaluated with the tryptic digests of standard proteins (α-casein, ß-casein, ovalbumin and bovine serum albumin). It is found that Zr-HCPA-SNPs are superior to Zr-CPA I-SNPs in phosphopeptide enrichment. Using Zr-HCPA-SNPs to trap phosphopeptides in α-casein digest, the detection limit was close to 50fmol based on MALDI-TOF MS analysis. Finally, Zr-HCPA-SNPs were used to directly isolate phosphopeptides from diluted human serum of healthy, diabetes and hypertension persons, respectively. Our results show that the constitution and level of phosphopeptides are remarkably different among the three groups, which indicate the powerful potentials of Zr-HCPA-SNPs in disease diagnosis and biomarker screening.