Signal amplification platform based on 2D MOF-on-MOF architectures-derived Co-decorated carbon@nitrogen-doped porous carbon for enhanced electrochemical acetaminophen sensing

Two-dimensional (2D) carbon-carbon hybrids derived from metal-organic frameworks (MOFs) are regarded as an intriguing type of electrode material in electrochemical sensing. In this work, a Co-decorated carbon@nitrogen-doped porous carbon heterostructure (Co/C@NC) was prepared via the simple calcination of 2D ZIF-L(Co)@ZIF-8. In this MOF-on-MOF precursor, the outer ZIF-8 layer not only prevents the collapse of ZIF-L(Co) during calcination but also endows the outer carbon an extended surface area and porous structure for more accessible active sites and a fast mass transfer process. Meanwhile, the formed CoNPs could facilitate the generation of graphitic carbon layers, which enhances electrocatalytic activity and boosted conductivity. Owing to these merits, the Co/C@NC-based sensor displays high electrochemical activity for acetaminophen (APAP) detection with a wide linear range (4 × 10^–7 - 2 × 10^–4 M) and a lower detection limit (8.2 × 10^–8 M). The constructed sensor has been utilized for the analysis of APAP in real samples, yielding acceptable recovery between 96.6% and 104.0%. This work presents an efficient and convenient method for designing MOF-on-MOF-derived 2D carbon-carbon hybrids, which hold a promising prospect in electrochemical analysis.