The chemical modification of hydrophobic polymer matrices is an alternative way to elchange their surface properties. The introduction of sulfonic groups in the polymer changes the surface properties such as adhesion, wettability, catalytic ability, and adsorption capacity. This work describes the production and application of chemically modified polyvinyl chloride (PVC) as adsorbent for dyes r...

The in vivo detection of ascorbic acid (AA), one of the physiologically important cerebral neurochemicals, is critical to probe and understand brain functions. Electrochemical sensors are convenient for AA detection. However, conventional electrochemical sensors usually suffer from several challenges, such as sluggish electron transfer kinetics for AA oxidation and poor reproducibility. To addr...

A simple, rapid and sensitive flow injection spectrophotometric method for determination of selenium (0.005-1.5 mug ml(-1)) is described. The method is based on the catalytic effect of Se(IV) on the reduction reaction of thionine (TN) with sulphide ion, monitored spectrophotometrically at 598 nm. The detection limit is 5 ng ml(-1) the relative standard deviation for eight replicate measurements...

In this work, a reversible sensor to assess the total Se(IV) content in samples is described. Pre-activated glass slides were spin-coated with 100 microL of a 20-h aged sol-gel mixture of 1 mL of tetramethoxysilane, 305 microL of 50 mmol L(-1) HCl and 2.0 mg of thionine. The flow-cell consisted of one of those slides as a window, and was filled with beads of a polystyrene anionic exchange resin...

An electrochemical biosensor based on functional composite nanofibers for hybridization detection of specific K-ras gene that is highly associated with colorectal cancer via multiple signal amplification strategy has been developed. The carboxylated multiwalled carbon nanotubes (MWCNTs) doped nylon 6 (PA6) composite nanofibers (MWCNTs-PA6) was prepared using electrospinning, which served as the...

In the present study, we fabricated an ultrasensitive sandwich-type electrochemical aptasensor for thrombin (TB) based on a triplex signal amplification strategy. The hemin/G-quadruplex horseradish peroxidase-mimicking DNAzyme (HRP-DNAzyme) as well as blocking reagent-horseradish peroxidase (HRP) and iron telluride nanorods (FeTe NRs) could simultaneously amplify the electrochemical signal of t...

The dog visual system is well suited to dim light conditions due to rod-dominated retina and the reflective tapetum. The topographical distributions of rods and thickness of the tapetum of the dog were quantified in retinal whole mounts stained with thionine, and spatial relationships among the tapetum, rod density and visual streak of high ganglion cell density were elucidated. The relationshi...