Dendrimer-modified magnetic nanoparticles as a sorbent in dispersive micro-solid phase extraction for preconcentration of metribuzin in a water sample

PAMAM-Functionalized Paper as a New Substrate for the Paper Spray Mass Spectrometry Measurement of Proteins

Paper surface functionalization with polyamidoamine (PAMAM) dendrimers has been developed for increased sensitivity analysis of proteins by paper spray mass spectrometry (PS-MS). PAMAM is a branched polymeric compound with an ethylenediamine core linked to repeating PAMAM units that generates an outer surface rich in primary amines. These positively charged amine groups can interact electrostatically with negatively charged residues (e.g., aspartate, glutamate) on the protein surface. PAMAM inner amide moieties can also promote hydrogen bonding with protein surface oxygens, making PAMAM a useful material for protein extraction. PAMAM-functionalized PS-MS paper strips were used to extract proteins from biofluids, dipped in acetonitrile to remove unbound constituents, dried, and then measured with PS-MS. The use of this strategy was optimized and compared with unmodified paper strips. PAMAM-functionalized paper substrates provided sixfold greater sensitivity for albumin, 11-fold for hemoglobin, sevenfold for insulin, and twofold for lysozyme. The analytical performance of the functionalized paper substrate was evaluated through the analysis of albumin in urine, achieving linearity with R² > 0.99, LOD of 1.1 μg mL^-1, LOQ of 3.8 μg mL^-1, precision better than 10%, and relative recovery 70-83%. The method was applied to quantify urinary albumin from nine anonymous patient samples (concentrations ranged from 6.5 to 77.4 μg mL^-1), illustrating its potential for the diagnosis of microalbuminuria. These data demonstrate the utility of paper modification with the PAMAM dendrimer for sensitive PS-MS analysis of proteins, opening a path for further applications in clinical diagnosis through the analysis of disease-related proteins.

PVA/Stevia/MIL-88A@AuNPs composite nanofibers as a novel sorbent for simultaneous extraction of eight agricultural pesticides in food and vegetable samples followed by HPLC-UV analysis

Herein, an electrospun composite from poly(vinyl alcohol) (PVA) and Stevia extract as a cross-linked nanofibrous was prepared with incorporating Fe-metal organic framework@Au nanoparticles (MIL-88A@AuNPs). The final composite was characterized, and then used as an efficient sorbent in pipette-tip micro solid-phase extraction (PT-µSPE) of eight selected pesticides in food samples followed by HPLC-UV analysis. Under the opted conditions, the linearity was in the range of 1.0-1000.0 ng mL^-1 for atrazine and ametryn, 3.0-1500.0 ng mL^-1 for tribenuron-methyl, metribuzin, profenofos and chlorpyrifos, 5.0 to 1500.0 ng mL^-1 for phosalone, and 5.0-2000.0 ng mL^-1 for malation with coefficient of determination (r²) ≥ 0.9943. The LODs (based on S/N = 3) ranged from 0.3 to 1.5 ng m L^-1. The relative standard deviations (RSDs) were between 5.2% and 6.6% (intra-day, n = 5) and 5.9%-7.4% (inter-day, n = 3) for three consecutive days. Ultimately, the capability of the method in various food samples was appraised with good recoveries (79.3 to 97.6%).

Recent innovations of nanotechnology in water treatment: A comprehensive review

Environmental pollution from organic and inorganic pollutants poses a threat to the ecosystem. Pollutant's prevalence and persistence have increased significantly in recent years. In order to enhance the quality of naturally accessible water to a level suitable for human consumption, a number of techniques have been employed. In this context, the use of cutting-edge nanotechnology to classical process engineering paves the way for technical encroachments in advanced water and wastewater technology. Nanotechnology has the potential to ameliorate the quality, availability, and viability of water supplies in the long run by facilitating reuse, recycling and remediation of water. The promising role of nanotechnology in wastewater remediation is highlighted in this paper, which also covers current advancements in nanotechnology-mediated remediation systems. Moreover, nano-based materials such as nano-adsorbents, photocatalysts, nano-metals and nanomembranes are discussed in this review of recent breakthroughs in nanotechnologies for water contaminant remediation.