Electrochemical determination of fenitrothion pesticide based on ultrathin manganese oxide nanowires/molybdenum titanium carbide MXene ionic nanocomposite and molecularly imprinting polymer.

A novel molecularly imprinted electrochemical sensor is presented based on one-dimensional ultrathin manganese oxide nanowires/two-dimensional molybdenum titanium carbide MXene (MnO2NWs@Mo2TiC2 MXene) for fenitrothion (FEN) determination. After the synthesis of MnO2NWs@Mo2TiC2 MXene ionic nanocomposite was successfully completed with a facile hydrothermal and the pillaring methods, a new type molecular imprinted electrochemical sensor based on MnO2NWs@Mo2TiC2 MXene was constructed with cyclic voltammetry (CV) polymerization including pyrrole monomer and FEN target molecule. After the characterization studies including spectroscopic, electrochemical and microscopic methods, the analytical applications of the prepared sensor were performed. A linearity of 1.0×10-9-2.0×10-8 mol L-1 was obtained and the values of the quantification limit (LOQ) and the detection limit (LOD) were 1.0×10-9 mol L-1 and 3.0×10-10 mol L-1, respectively. The studies of selectivity, stability and reproducibility of the constructed sensor based on MnO2NWs@Mo2TiC2 nanocomposite and molecularly imprinting polymer (MIP) were carried out in detail. Finally, the developed sensor was applied to white flour samples with the values close to 100%.

Synthesis and acetylcholinesterase enzyme inhibitory effects of some novel 4,5-Dihydro-1H-1,2,4-triazol-5-one derivatives; an in vitro and in silico study.

In this study, a series of novel Schiff bases (4a-4h) containing 1,2,4-triazole structure were synthesized through a condensation reaction of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones with 3-(4-methylbenzenesulfonyloxy)-benzaldehyde. The structures of 3-alkyl(aryl)-4-[3-(4-methylsulfonyloxy)-benzylidenamino]-4,5-dihydro-1H-1,2,4-triazol-5-ones (4a-h) were determined through a range of spectroscopic techniques (FT-IR, 1H NMR, 13C NMR, and elemental analysis). In addition, enzyme inhibitory properties of the newly synthesized Schiff bases were determined against acetylcholinesterase (AChE). Their Ki values were calculated in the range of 0.70 ± 0.07-8.65 ± 5.6 µM. Besides, their IC50 values were calculated in the range of 0.43-3.87 µM. Finally, in silico molecular docking interactions of the compounds with AChE target enzyme (PDB ID:4EY7) were evaluated using Chimera and AutoDock Vina softwares. The lowest binding energy levels (-12.0 kcal/mol) of the compounds 4e and 4g with AChE target enzyme were verified the best binding affinities and molecular interactions.Communicated by Ramaswamy H. Sarma.

A novel sandwich-type SERS immunosensor for selective and sensitive carcinoembryonic antigen (CEA) detection.

Monitoring the malignant tumors via cancer biomarkers is very significant process. Nonetheless, the practical clinical applications need selective and sensitive analytical methods/techniques. In this study, a novel sandwich type immunosensor based on surface-enhanced raman scattering (SERS) was presented including 4-mercaptobenzoic acid labeled MoS2 nanoflowers@Au nanoparticles (MoS2 NFs@Au NPs/ MBA) as CEASERS tag and Fe3O4@Au nanoparticles functionalized delaminated Ti3C2Tx MXene (Fe3O4 NPs@Au NPs/d-Ti3C2TX MXene) as SERS magnetic supporting substrate for carcinoembryonic antigen (CEA) detection. Especially, the determination of single molecule by using SERS method enables early diagnosis of major diseases. In addition, this technique can be utilized for multiplex analyzes owing to narrow well-resolved peaks. The prepared CEASERS tag and SERS magnetic supporting substrate were characterized by scanning electron microscope (SEM), x-ray diffraction (XRD) method, x-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and fourier transform infrared spectroscopy (FTIR). A linearity of 0.0001-100.0 ng mL-1 was observed with high sensitivity. Finally, sandwich type immunosensor demonstrated good selectivity and stability for target CEA recognition in plasma sample.

A novel and ultrasensitive sandwich-type electrochemical immunosensor based on delaminated MXene@AuNPs as signal amplification for prostate specific antigen (PSA) detection and immunosensor validation.

In this study, an ultra-sensitive electrochemical immunosensor for PSA detection was designed. Firstly, gold nanoparticles (AuNPs)/p-aminothiophenol (ATP) functionalized graphene oxide (GO) composite (AuNPs-ATPGO) was constructed and modified to glassy carbon electrode (AuNPs-ATPGO/GCE). AuNPs-ATPGO/GCE was utilized as immunosensor platform to increase the amount of PSA antibody1 (Ab1). After that, self-assembled delaminated MXene-gold nanoparticles (d-Ti3C2TX MXene@AuNPs) was used to label PSA seconder antibody2 (Ab2) as signal amplification. The prepared AuNPs-ATPGO, d-Ti3C2TX MXene@AuNPs and electrochemical immunosensor was charecterized by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), scanning electron microscope (SEM), x-ray diffraction (XRD) method, x-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR). The linearity range and detection limit (LOD) were obtained as 0.01-1.0 pg mL-1 and 3.0 fg mL-1, respectively.