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/Ndoped 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 mu M and the detection limits were determined to be 0.3 mu M and 0.4 mu M, 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.