A disposable electrochemical sensor for simultaneous detection of sulfamethoxazole and trimethoprim antibiotics in urine based on multiwalled nanotubes decorated with Prussian blue nanocubes modified screen-printed electrode

The online monitoring of drug levels in body fluids represents a visionary solution for personalized medicine that could facilitate the patient treatment. Screen printed electrodes (SPE) offer possibilities of miniaturization and sample volume reduction, in addition to high sensitivity and low cost provided by electrochemical techniques. The present work proposes a novel electrochemical sensor modified with multiwalled carbon nanotubes decorated with Prussian blue nanocubes (MWCNT/PBnc). MWCNT/PBnc composite combines the high presence of catalytic active sites in PBnc edges with MWCNT platform which enhances PBnc stability in neutral pH. Simultaneous detection of sulfamethoxazole (SMX) and trimethoprim (TMP) were performed by differential pulse voltammetry. The MWCNT/PBnc film exhibited high selectivity and sensitivity toward SMX and TMP. The MWCNT/PBnc/SPE achieved a linear range of 0.1-10.0 mu mol L (1) with limit of detection (LOD) of 60 nmol L (1) for TMP, while for SMX, a linear range of 1.0-10.0 mu mol L (1) with LOD of 38 nmol L (1) was found. The sensor enabled the simultaneous determination of SMX and TMP in artificial urine with recovery between 91.3 to 101% and its performance can lead to feasible and promising biomedical applications in real time for point-of-care testing. (C) 2016 Elsevier Ltd. All rights reserved.