1：Experimental Design and Method Selection:

The study designed a sensor based on gold nanoparticles (AuNPs) modified with adenosine triphosphate (ATP) and rhodamine B (RB) to detect organophosphate pesticides through colorimetric and fluorescent changes due to nanoparticle aggregation. The method leverages the strong Au-S bond and ATP's affinity to AuNPs for specificity.

2：Sample Selection and Data Sources:

Pesticide samples including ethoprophos, chlorpyrifos, profenofos, trichlorfon, omethoate, monocrotophos, isocarbophos, and malathion were purchased from commercial sources. Tap water samples were used for real-world application testing.

3：List of Experimental Equipment and Materials:

Equipment includes a Shimadzu 2600 spectrophotometer for UV-Vis absorption measurements (400-900 nm), a Hitachi F7000 fluorescence spectrophotometer for fluorescence intensity (540-700 nm, excitation at 520 nm), an inverted fluorescence microscope (Olympus) for imaging, a transmission electron microscope (Hitachi HT7700) for morphology imaging, and a particle size analyzer (Nano-ES90, Malvern Instruments) for hydrodynamic size distribution. Materials include gold(III) chloride trihydrate, sodium citrate tribasic dihydrate, ATP, rhodamine B, and various pesticides.

4：Experimental Procedures and Operational Workflow:

Citrate-capped AuNPs were synthesized, then modified with ATP and RB to form RB-AuNPs. Pesticide solutions were added to AuNP solutions, and changes in color and fluorescence were measured after vortexing and incubation. Sensitivity and specificity tests were conducted with varying concentrations and pH conditions.

5：Data Analysis Methods:

Data were analyzed using UV-Vis and fluorescence spectroscopy. The limit of detection (LOD) was calculated as 3σ/k, where σ is the standard deviation of blank tests and k is the slope of the linear fitting equation. Statistical analysis included calculating recovery rates and relative standard deviations for real sample tests.