•A novel SACe-N-C nanozyme with high POD-like activity was used to construct bioactive paper.•The bioactive paper offered a portable approach to detect pesticide residues in fruits and vegetables within 30 min.•An on-site portable testing device was proposed by integrating SACe-N-C bioactive paper into 3D printed platform.•The proposed assay for omethoate, methamidophos, carbofuran, and carbosulfan showed an acceptable limit of detection. Rapid detection of pesticide residues based on enzyme mimics has recently attracted much interest. However, most nanozymes have low activity. Herein, a “single-atom Ce-N-C nanozyme” (SACe-N-C nanozyme) was rationally devised and verified to mimic peroxidase (POD-like) with superior activity. Based on its high POD-like activities and cascaded catalytic reactions with acetylcholinesterase (AChE), we constructed a bioactive paper for the detection of pesticide residues, which offered a portable approach to monitor fruits and vegetables within 30 min. More importantly, a 3D printed platform was integrated on the basis of SACe-N-C bioactive paper to achieve on-site portable testing of omethoate, methamidophos, carbofuran, and carbosulfan, showing limits of detection (LODs) of 55.83, 71.51, 81.81, and 74.98 ng/mL, respectively. The recovery rates were 84.09–104.68%. This study provided new insight into the design of novel single-atom nanozymes for cascaded catalytic detection and other rapid detection applications with high efficiency and low cost.