Sm2O3 Nanorod modified Graphite Paste Electrode for Trace Level Voltammetric Determination of Acetaminophen and Ciprofloxacin

Samarium oxide (Sm2O3) nanorod was synthesized through a sol-gel method in the presence of poly (ethylene glycol) as a structure-directing subagent. The transformation of the crystalline phase, crystallinity, bonding configurations, and morphology with calcination temperature was investigated by powder x-ray diffraction, FESEM, XPS, and TEM. Furthermore, various spectroscopic analyses were done by FTIR, UV-Vis, and photoluminescence. A composite of Sm2O3 nanorod and graphite was used to prepare an electrochemical sensor for the detection of two different drug molecules in a binary mixture, namely acetaminophen (AC) and ciprofloxacin (CP). The effects of the crystalline phase on the electrocatalytic activity were analyzed. The modified electrode showed high sensitivity (93 µA µM-1cm-2 for AC and 6.5 µAµM-1cm-2 for CP) towards the drug molecules during the voltammetric determination. An optimized composition (3:7 Sm2O3: Graphite) of the modified electrode was shown the best analytical performances. The strongest differential pulse voltammetric oxidations peaks for AC and CP were at around 533±3 mV and 976±043 mV, respectively. Anodic oxidations peaks were well separated for effective analysis within a mixture. The sensor response was linear within the concentration range of 0.001-0.01-300 μM and 0.05-1-170 μM for AC and CP, respectively. The detection limits were 0.1 nM for AC and 5 nM for CP (S/N 3). The Sm2O3-9-3/GP electrode showed excellent analytical performance when analyzing spiked urine and pharmaceutical sample.