Heide Hartman (beetgreen94)

A label-free electrochemical immunosensor based on polyaniline (PANI) micellar electrode was firstly fabricated for direct AMH detection. To control the size regularity of PANI, a micelle-based method using ammonium peroxydisulfate (APS) as a reducing agent was employed in the polymerization process. The Anti-AMH antibodies were readily immobilized onto PANI via peptide bond to enhance the sensor specificity and sensitivity. This sensor was applied for the detection of AMH, an ovarian response indicator in female related to residual eggs during a woman's monthly cycle. The sensor performances were systematically investigated by differential pulse voltammetry. GW806742X clinical trial The anodic peak current decreases with the increase of AMH concentration owing to blocking of electron transfer by AMH. Under the optimal conditions, this sensor offers high sensitivity with a low detection limit of 0.1 ng mL-1 and a wide linear range of 0.1-4 ng mL-1, which is sensitive enough to indicate the ability to produce eggs during a woman's monthly cycle. Furthermore, this system requires lower sample volume (5 μL), while offers the simple fabrication with low cost and no synthetic challenge and faster analysis compared with a standard ELISA. Ultimately, this sensor was successfully applied for the detection of AMH in human serum with satisfactory results. Thus, it might be an alternative tool for AMH screening in clinical setting.In the present study we report the simultaneous determination of glutathione (GSH) and glutathione disulfide (GSSG) by an automated flow method based on the concept of zone fluidics. GSH is quantified selectively in a first run by reaction with o-phthalaldehyde at a mildly basic pH = 8, without interference from GSSG. The latter was also found to react with o-phthalaldehyde but in highly basic medium (0.2 mol L-1 NaOH) and was determined after masking of GSH with N-ethyl-maleimide. Detection was carried out fluorimetrically at 340/425 nm. The flow procedure was optimized and validated, paying special attention to its selectivity. The LOD was 60 nmol L-1 for GSH and for 53 nmol L-1 for GSSG, while the within-day and day-to-day precisions were better than 1.5% and 3.7% respectively. Real yeast samples were successfully analyzed without matrix effect (-2.0 to +4.1%) and with percent recoveries being in the range of 87.0 and 103.3%.The determination of sulfide anion in a variety of waters (e.g. wastewaters and natural waters) even at low concentration (i.e. in the μM range) is essential due to its high toxicity, corrosivity and unpleasant smelling proprieties. Despite several methodologies are dedicated to aqueous sulfide determination, most of them need sampling/transport steps - which is no adequate to sulfide due to its reactivity and instability - resulting in critical analytical bias. In this study, we present a fully modular and portable 3D-printed platform for in-situ aqueous sulfide determination. The analytical device is based on H2S vapor generation from the sulfide sample solution by addition of H3PO4 followed by collection in a miniaturized cuvette (μCuvette) containing few microliters of Fluorescein Mercury Acetate (FMA), a fluorescent dye. The chemical reaction results in fluorescence quenching of the dye at 530 nm when excited at 470 nm. A light-emitted diode (LED) emitting at 470 nm and powered with 9 V-battery based cirf volatile substances using absorbance, reflectance or fluorescence measurements with smartphones.In this work, gel electro-membrane extraction (G-EME) method is suggested for extraction and determination of propranolol and atenolol in complex biological samples. An in-house membrane based on agarose was used as green and biodegradable gel membrane. Essential chemical parameters that influence on extraction efficiency were tested, optimized and evaluated via a central composite design (CCD) and response surface methodology (RSM). Optimal conditions for extraction of drugs from th