Bjerresawyer7002

Doping is often used to alter or improve the properties of nanomaterials. In this work, a novel glucose-based nitrogen-doped carbon dots (Glc-NCDs)-bonded silica stationary phase (Sil-Glc-NCDs) was synthesized and characterized carefully. Glc-NCDs were prepared using glucose and aspartic acid as carbon and nitrogen sources, and then grafted on silica surface via isocyanatopropyl as linker using deep eutectic solvents as reaction medium. The synthesis was confirmed by elemental analysis, Fourier transform infrared spectroscopy and microscopic imaging techniques. And then Sil-Glc-NCDs were packed in the stainless columns for hydrophilic interaction chromatography (HILIC). Due to the synergistic effect between the functional groups of doped carbon dots, Sil-Glc-NCDs column showed enhanced separation selectivity compared with previous non-doped Sil-Glc-CDs column. Sil-Glc-NCDs column can be used for separation of base, nucleosides and antibiotics etc. Berzosertib research buy This column was successfully applied to determine the content of roxithromycin in the capsule, which was found that the concentration was 2.45 mg/mL.In the present work, a magnetic metal-organic framework composite (Fe3O4@TGA@TMU-6) was synthesized and used as an adsorbent for magnetic solid-phase extraction (MSPE) of some organophosphorus pesticides (phosalone, chlorpyrifos and, profenofos) in rice and environmental water samples. Extraction, separation and determination of the analytes were performed by MSPE-HPLC-UV. Due to the large surface area and unique porous structure of the metal-organic frameworks (MOFs) as well as π-π and hydrophobic interactions between the analytes and the MOF ligands, the prepared sorbents showed a high affinity towards the target analytes. The affecting parameters on the extraction efficiency, including type and volume of eluent, pH, amount of MFC, extraction time, salt effect and desorption time were investigated and optimized. Under optimum conditions, calibration curves were found to be linear in the range of 7.5-75 μg L-1, 10-100 μg L-1, and 10-150 μg L-1 for phosalone, chlorpyrifos, and profenofos in water samples, respectively. The LODs (based on S/N = 3) were 0.5, 1 and 0.5 μg L-1 for phosalone, chlorpyrifos, and profenofos in water samples, respectively.Herein, we report the simple and inexpensive approach for the large-scale fabrication of uniform bottom-up Surface Enhanced Raman Spectroscopy (SERS) substrate. SERS substrate was fabricated by controlled sputtering of 10 nm thick gold film on self-assembled silica nanoparticles (SiNPs) of ~120 nm on glass substrates. The SERS detection has been firstly demonstrated using Rhodamine B as a Raman probe molecule with a detection limit of 10-10 M on Au sputtered SiNPs (i.e., Au@SiNPs). The experimental Raman enhancement from 0 to 6 was achieved on Au@SiNPs due to the generation of multiple SERS hotspot. To combat blood serum fouling, the zwitterionic modification of l-cysteine was done on Au@SiNPs substrates which lowered blood serum fouling by 48%. Our SERS-based sensor demonstrated high reproducibility for the detection of Doxorubicin in undiluted blood serum with a limit of detection of 20 nM, which greatly exceeded the detection range of available methodologies. We envision that the translation of this SERS substrate for the detection of chemo-drugs like Doxorubicin will assist clinicians in making rapid and/or early decisions in patients undergoing sustained chemotherapy to lower its side-effects or to incorporate other treatment methodologies as an option for Personalized treatment.A new method based on fluorescent probe of iron quantum cluster has been proposed for rapid detection of Escherichia coli (E. coli). The iron quantum cluster was synthesized using hemoglobin as both a source of iron and a protective agent (Hb-FeQCs). The investigation of the sensitivity of Hb-FeQCs towards metal ions showed a highly selective turn off fluorescence for Cu2+. It suggests that Cu2+ can induce fluorescence quenching by binding to amino acids of Hb. The ability of E. coli bacteria to capture and reduce of Cu ions caused to efficient recovery of the fluorescence of Hb-FeQCs from Cu2+-caused quenching. This probe has a satisfactorily linear range of 0.35-35 μM for Cu2+ under the optimal iron quantum cluster concentration (500 μg/mL) with an 85 nM detection limit. Rapid and facile detection of E.coli bacteria with the limit of detection around 8.3 × 103 CFU/mL was successfully achieved in the artificially contaminated urine, tap water, and DMEM samples within 30 min. The fluorescence recovery was investigated by different types of bacteria and only E. coli revealed 56% recovery which related to its capability to Cu2+ reduction and the great potential of the fluorescent probe for rapid detection of pathogenic E. coli bacteria. Furthermore, the Hb-FeQCs can detect E. coli bacteria in an infected urine sample by retrieving up to 74% of its fluorescence which is helpful to accelerate the diagnosis and treatment of urinary tract infection (UTI).Voltammetric determination of Tartrazine (Tz) and Brilliant Blue FCF (BB) in their mixture using novel type of carbon black-polyethylene composite electrode (CBPCE) with renewable surface modified by carbon ink (CI) was developed. Electrochemical properties of the tested dyes were investigated in 0.1 mol L-1 Britton-Robinson (BR) buffer by cyclic voltammetry (CV) and linear scan voltammetry (LSV). Simultaneous determination of the dyes is based on the application of supporting electrolytes with different pH 2.0 for Tz and 10.0 for BB. Under the optimum experimental conditions, linear concentration dependences in the concentration ranges from 0.037 to 1.38 μmol L-1 for Tz and from 0.025 to 2.52 μmol L-1 for BB were obtained by LSV in the first-order derivative mode. Limits of detection (LODs) for Tz and BB were 0.019 and 0.011 μmol L-1, respectively. The modified electrode showed good stability and reproducibility and was successfully applied for the determination of the mixture Tz and BB in a candy and soft drink products.Indirect Nano-sensing are indispensable chemical sensory points that make use of the unique properties of nanoparticles to derive information about it to our macroscopic world. Precious Silver nanoparticles have become more attractive in many areas of healthcare and life sciences leading to massive industrial production and increase of environmental exposure which may lead to Nanotoxicity accompanied by the release of Ag+ ions. A reversible silver selective screen-printed electrode was fabricated, optimized, and validated. A wide linearity range of 1 × 10-6 - 1 × 10-2 M was obtained, with a LOD that reaches 1.5 × 10-7 M and a typical slope of monovalent cationic compounds of 59.6 mV/decade. It showed high selectivity towards the cationic Ag+ ion activity in presence of the negatively charged citrate capped silver nanoparticles (Cit-AgNPs). The fabricated sensor has been used for tracking the decrease of Ag+ activity during the reduction of AgNO3 with tri-sodium citrate during the Bottom-up synthesis of Cit-AgNPs at different temperature (60, 70 and 80 °C).