COVID-19 chloroquine drug detection using novel, highly sensitive SnO2-based electrochemical sensor

A highly sensitive, selective, stable, and cost-effective SnO2-based electrochemical sensor is reported for the detection of chloroquine phosphate (CQP). Hydrothermal synthesis is used to synthesize SnO2 nanoparticles, which are mixed with graphite and form a highly electrochemically active composite. The SnO2 nanoparticles and SnO2/graphite composite are fully characterized physico-and electrochemically. Using the optimal SnO2/graphite composite, an excellent analytical performance is demonstrated with an electrode sensitivity of 35.7 & mu;A/& mu;M.cm2, a linear range of 0.1- 23.3 & mu;M, and limits of detection and quantification of 0.01 & mu;M and 0.04 & mu;M, respectively. High CQP selectivity with minimal interference at 100 x concentration of interferents is shown. The sen-sor is also highly repeatable and reproducible with RSD of 2.46 % and 1.86 %, respectively, and can retain > 85 % of its activity upon storage. The validity of the new sensor for real sample anal-ysis is shown by applying it to CQP tablets using the standard addition method, obtaining an excel-lent percentage recovery of -102 %. The low cost, facile processing, and superior performance of the SnO2/graphite electrode make it an up-and-coming candidate for the commercial electrochem-ical detection of CQP and other small molecules. & COPY; 2023 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).