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A novel highly active silver single-atom catalyst (AgSAC) was prepared by a microwave-assisted solvothermal method using silver covalent organic frameworks (AgMOF) as precursors. It was characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), infrared (IR), and surface-enhanced Raman scattering (SERS). The experiment found that AgSAC has excellent catalytic performance and can heavily catalyze the nano-reaction of chloroauric acid-malic acid (HAuCl 4 –H 2 Mi) to generate gold nanoparticles (AuNPs). The produced AuNPs have strong SERS, resonance Rayleigh scattering (RRS) and surface plasmon resonance absorption (Abs) signals. Aflatoxin B1 aptamer (Apt AFB1) can be adsorbed to the surface of AgSAC through electrostatic interaction, to reduce the catalytic activity of AgSAC and the SERS/RRS/Abs signal of the system. When the target molecule (AFB1) was added, it will specifically bind to Apt AFB1 and release AgSAC, restoring the catalytic activity of AgSAC, thereby restoring the SERS/RRS/Abs signal of the system. Based on this, a simple and sensitive aptamer sensing analysis platform for trace AFB1 was established, and a reasonable catalytic amplification mechanism of AgSAC was proposed. The SERS method exhibited the highest sensitivity, with a linear range of 0.005–0.225 μg/L and a detection limit of 0.002 μg/L. Principle of aptamer-mediated SERS/RRS for AFB1 based on AgSAC catalysis. [Display omitted] • A highly active silver single-atom catalyst (AgSAC) was synthesized with AgMOF. • A new AgSAC-HAuCl 4 -H 2 Mi catalytic indicator was constructed. • The nanocatalytic amplification reaction was coupled with aptamer mediation. • A highly sensitive SERS/RRS platform was proposed for trace Aflatoxin B1. [ABSTRACT FROM AUTHOR]