A dual-ratiometric electrochemical sensor based on Cu/N-doped porous carbon derived from Cu-metal organic framework for acetaminophen determination

Ratiometric electrochemical sensors with internal correction function have received extensive attention due to their good resistance to complex factors. Herein, a dual-ratiometric electrochemical sensor was fabricated for the determination of acetaminophen (AP) based on glass carbon electrode (GCE) modified by methylene blue /Cu/N-doped porous carbon (MB/Cu/N-C) composite. The Cu/N-C derived from the calcination of Cu based metal–organic framework not only had good electrochemical performance, but also provided a redox signal as an internal reference and plenty of attachment sites for another reference molecules-MB. The electrochemical results displayed that MB/Cu/N-C/GCE had three peaks at 0.34, 0.04, and −0.29 V when AP was present, which came from the electro-oxidation of AP, Cu/N-C, and MB, respectively. Two ratiometric signals, namely, IAP/IMB and IAP/ICu/N-C, were utilized to the detection of AP. The IAP/IMB and IAP/ICu/N-C were linearly correlated with the AP concentrations in the range of 0.5 to 150.0 μM and the detection limits were determined to be 0.3 μM and 0.4 μM, respectively. Meanwhile, this sensor was utilized to determinate AP in pharmaceutical tablet samples with good recoveries, which displayed the great potential of MB/Cu/N-C/GCE in clinical applications.