Electrochemical detection of ractopamine at arrays of micro-liquid | liquid interfaces

Abstract

The behaviour of protonated ractopamine (RacH(+)) at an array of micro-interfaces between two immiscible electrolyte solutions (micro-ITIES) was investigated via cyclic voltammetry (CV) and linear sweep stripping voltammetry (LSSV). The micro-ITIES array was formed at silicon membranes containing 30 pores of radius 11.09±0.12 µm and pore centre-to-centre separation of 18.4±2.1 times the pore radius. CV shows that RacH(+) transferred across the water |1,6-dichlorohexane µITIES array at a very positive applied potential, close to the upper limit of the potential window. Nevertheless, CV was used in the estimation of some of the drug's thermodynamic parameters, such as the formal transfer potential and the Gibbs transfer energy. LSSV was implemented by pre-concentration of the drug, into the organic phase, followed by voltammetric detection, based on the back-transfer of RacH(+) from the organic to aqueous phase. Under optimised pre-concentration and detection conditions, a limit of detection of 0.1 µM was achieved. In addition, the impact of substances such as sugar, ascorbic acid, metal ions, amino acid and urea on RacH(+) detection was assessed. The detection of RacH(+) in artificial serum indicated that the presence of serum protein interferes in the detection signal, so that sample deproteinisation is required for feasible bioanalytical applications.

Electrochemical Behavior and Detection of Diclofenac at a Microporous Si3N4 Membrane Modified Water–1,6-dichlorohexane Interface System

“…Therefore, the experimental currents obtained are compared with the theoretical currents in the case inlaid and recessed interfaces. In case, a steady-state current (radial diffusion control) had been achieved [22,51], thus, the limiting current is defined as for an inlaid disc microelectrode (Equation (1))…”

“…However, Most ITIES studies on ionizable drugs have focused on understanding the lipophilicity for pharmacological drugs through voltammetric investigations via a polarized ITIES [17,18]. Despite several works published for electrochemical studies of ion transfer responses of various drugs across the ITIES [19][20][21], much fewer reports have been represented for the design of liquid-liquid interface as a sensing platform for the detection of drugs, including ractopamine [22], daunorubicin [23], α1-acid-glycoprotein [24], and propranolol [25]. We present here a novel sensing platform based on an array of microporous able to detect ionic species in a biological fluid.…”

Research into regularities of pore formation on the surface of semiconductors

“…Galvani potential φ 1 , 2 (difference in electrical potentials between two points in the phases semiconductor/electrolyte is determined by formula (1) [29]:…”

Applications of Electrochemistry at Liquid/Liquid Interfaces for Ionizable Drug Molecule Sensing

“…Some other examples of drug molecule investigated includes a protonated ractopamine (RacH + ) analysis in artificial serum based on RacH + transfer across a microhole supported water/1,6-DCH interface using linear sweep stripping voltammetry (LSSV) with preconcentration of RacH + in the gel via applying the drug transfer potential. 28) As well as detecting RacH + , the interfering effect of serum protein on the detection signal was investigated, which should be considered when dealing with any biological fluid analysis.…”