1：Experimental Design and Method Selection:

The study designed a fluorescence polarization (FP) assay using graphene oxide (GO) as a signal amplifier and FAM-labelled aptamers for AFB1 detection. The principle involves adsorption of aptamers on GO via π–π stacking and electrostatic interactions, leading to high FP values, which decrease upon AFB1 binding due to dissociation from GO.

2：Sample Selection and Data Sources:

Rice samples were purchased from a market, and standard AFB1 and other mycotoxins (ZEN, FB1, OTA) were obtained from commercial sources. Aptamers were synthesized and purified.

3：List of Experimental Equipment and Materials:

Equipment includes a Synerg H1 multi-detection microplate reader, UV-1800 UV-Vis spectrophotometer, KQ-300E ultrasonic cleaning machine, JEM-2100HR TEM, Dimension ICON AFM, black 96-well plate, and MilliDirect-Q3 ultra-pure water purifier. Materials include AFB1, FB1, ZEN, OTA, GO powders, rice, FAM-labelled aptamer, binding buffer (Tris-HCl, KCl, NaCl, MgCl2), and other analytical reagents.

4：Experimental Procedures and Operational Workflow:

Steps include preparation and characterization of GO nanosheets, optimization of aptamer and GO concentrations, optimization of incubation times, pH effects testing, preparation of rice sample extracts, detection of AFB1 using the FP assay, specificity tests with other mycotoxins, and recovery tests.

5：Data Analysis Methods:

FP values were measured using a microplate reader. Linear relationships were analyzed, LOD was calculated as 3σ/S, and recoveries were computed based on detected vs. added concentrations.