Electrochemical sensing of acetaminophen in biofluids, pharmaceutical and environmental samples using cobalt hexacyanoferrate decorated iron terephthalate metal organic framework

Herein, a highly sensitive, cost-effective, and sustainable electrochemical sensor was developed for the selective sensing of acetaminophen (ACP) in actual samples using cobalt hexacyanoferrate (CHCF) incorporated iron terephthalate metal organic framework (FMF). The CHCF-FMF was sustainably synthesized and characterized using FTIR, XRD and SEM with EDX analysis. Using CHCF-FMF, a modified electrode was fabricated by drop-casting it over a glassy carbon, which on voltammetric investigations, revealed the presence of Co2+/3+ redox couple with a formal potential of 0.51 V. Further, the designed sensor was employed for the electrocatalytic oxidation of ACP, which showed a linear detection range from 0.05 to 7.37 mM with a sensitivity and detection limit of 100.64 µA/mM/cm2 and 13 µM, respectively. Furthermore, the developed CHCF-FMF/GCE sensing system is highly facile and robust, and it has demonstrated excellent stability, selectivity, repeatability, and good reproducibility. The superior performance was attributed to the in-situ formation of CHCF over FMF, which efficiently arranged them to augment the electrochemical and electrocatalytic properties. Besides, the sensor was employed to determine ACP in blood serum, commercial tablets, and environmental samples, which showed recovery ranges of 96.2%–106.2%. This work provides a novel strategy for designing catalytically active sites at the molecular level, which opens a new avenue in fine-tuning MOFs for their applicability in medical diagnostics, point-of-care, industrial and environmental monitoring devices.