Investigation of the Real-Time Release of Doxycycline from PLA-Based Nanofibers.

Electrospun mats of PLA and PLA/Hap nanofibers produced by electrospinning were loaded with doxycycline (Doxy) through physical adsorption from a solution with initial concentrations of 3 g/L, 7 g/L, and 12 g/L, respectively. The morphological characterization of the produced material was performed using scanning electron microscopy (SEM). The release profiles of Doxy were studied in situ using the differential pulse voltammetry (DPV) electrochemical method on a glassy carbon electrode (GCE) and validated through UV-VIS spectrophotometric measurements.

Preparation and Characterization of Doxycycline-Loaded Electrospun PLA/HAP Nanofibers as a Drug Delivery System.

The present study aimed to prepare nanofibers by electrospinning in the system polylactic acid-hydroxyapatite-doxycycline (PLA-HAP-Doxy) to be used as a drug delivery vehicle. Two different routes were employed for the preparation of Doxy-containing nanofibers: Immobilization on the electrospun mat's surface and encapsulation in the fiber structure. The nanofibers obtained by Doxy encapsulation were characterized using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric (TG) and differential thermal analyses (DTA) and scanning electron microscopy (SEM).

Second-order derivative of square-wave voltammetry for determination of vanillin at platinum electrode.

A simple and sensitive method of data treatment by second-order derivative square wave voltammetry (SD-SWV) was developed for the determination of vanillin at a platinum electrode. It was shown that the irreversible oxidation reaction is controlled by the adsorption and occurs following a mechanism involving two electrons, similar to other phenolic derivatives. The experimental parameters of SWV which exert influence on vanillin determination, such as frequency, pulse amplitude, or step potential, were optimized.

Glassy Carbon Electrodes Modified with Ordered Mesoporous Silica for the Electrochemical Detection of Cadmium Ions.

Four different samples of ordered mesoporous silica powders (MCM-41 and SBA-15) and amino-functionalized mesoporous silica (MCM-41-NH and SBA-15-NH) were used to prepare modified glassy carbon electrodes coated with ion-exchange polymer Nafion to be used for the electrochemical detection of Cd(II). The mesoporous silica samples were characterized through transmission electron microscopy, small-angle X-ray scattering, and N-adsorption/desorption isotherms. The electrodes were characterized by using square wave anodic stripping voltammetry.

Composite electrodes with carbon supported Ru nanoparticles for H2O2 detection.

A new carbon paste electrode (CPE) incorporating Ru - nanoparticles (RuNP) stabilized on graphite powder was developed for H(2)O(2) amperometric detection. Cyclic voltammetric measurements, performed in phosphate buffer solutions at different potential scan rates and different potential ranges were carried out in order to evaluate the electrochemical behavior of the CPE-RuNP modified electrodes. From amperometric measurements performed at -0.

Nitrite detection in meat products samples by square-wave voltammetry at a new single walled carbon naonotubes--myoglobin modified electrode.

A new modified electrode was realized in a simple way, consisting by the immobilization of a myoglobin (My) - single walled carbon nanotubes (SWCNT) mixture on the surface of a graphite electrode with a Nafion film. The cyclic voltammetry investigations realized with the obtained electrode (G/My-SWCNT/Nafion) showed a voltammetric signal due to a one-step redox reaction of the surface-confined myoglobin, in a deaerated 0.1 M phosphate buffer, pH 7.

Sensitive detection of organophosphorus pesticides using a needle type amperometric acetylcholinesterase-based bioelectrode. Thiocholine electrochemistry and immobilised enzyme inhibition.

An acetylcholinesterase (AChE) based amperometric bioelectrode for a selective detection of low concentrations of organophosphorus pesticides has been developed. The amperometric needle type bioelectrode consists of a bare cavity in a PTFE isolated Pt-Ir wire, where the AChE was entrapped into a photopolymerised polymer of polyvinyl alcohol bearing styrylpyridinium groups (PVA-SbQ). Cyclic voltammetry, performed at Pt and AChE/Pt disk electrodes, confirmed the irreversible, monoelectronic thiocholine oxidation process and showed that a working potential of +0.