Serum-protein effects on the detection of the B-blocker propranolol by ion-transfer voltammetry at a micro-ITIES array

Abstract

In this work, the effect of the serum protein, bovine serum albumin (BSA), on the detection of propranololin artificial serum by ion-transfer voltammetry at an array of micro-interfaces between two immiscibleelectrolyte solutions (ITIES) is presented. Cyclic voltammetry (CV), differential pulse voltammetry(DPV), and differential pulse stripping voltammetry (DPSV) were examined for the detection of low concentrationsof propranolol. Both CV and DPV had an interference effect from BSA, manifested as lowercurrents in the presence of the protein. DPSV proved to be the most effective technique, enabling thedetection of 0.05M propranolol in the presence of BSA. The DPSV method employed a preconditioningstep as well as a preconcentration step followed by the analytical signal generation step. The latterwas based on the back-transfer of the drug across the ITIES. The preconcentration step was crucialto prevention of the adverse effects of BSA on the voltammetric detection. These results demonstratethat serum-protein effects on drug detection at low concentrations can be eliminated by use of DPSV atarrays of ITIES. CVs of propranolol with increasing concentrations of BSA revealed the influence of thedrug–protein binding interaction, with decreases in current but no change in transfer potential. Therapeuticconcentrations of propranolol were detected, demonstrating the viability of this approach forbioanalytical investigations.