1：Experimental Design and Method Selection:

The study involved designing an SPR sensor with a composite recognition element synthesized via one-pot in situ polymerization using polydopamine. Methods included FTIR, SEM, XRD, Raman spectroscopy, contact-angle measurements, and SPR kinetic analysis.

2：Sample Selection and Data Sources:

Samples included GO, L-Trp, D-Trp, dopamine hydrochloride, and other chemicals. Data were obtained from experimental measurements.

3：List of Experimental Equipment and Materials:

Equipment included Biacore3000 SPR system, XL30 TMP SEM, Vertex 70 FTIR spectrometer, JEM-2100F TEM, LabRam HR 800 Raman spectrometer, JC-2000C1 tensiometer, and Milli-Q water system. Materials included graphite, H2SO4, H2O2, L-Trp, D-Trp, dopamine hydrochloride, Tris, APS, b-mercaptoethylamine, and gold-coated SPR chips.

4：Experimental Procedures and Operational Workflow:

The SPR chip was cleaned and modified with a SAM. GO was reduced and polymerized with PDA and L-Trp in a one-pot process. The composite was immobilized on the chip, and SPR measurements were conducted at 25°C with PBST buffer. Data were analyzed using Biacore software.

5：Data Analysis Methods:

Data were analyzed using a one-to-one Langmuir binding model for kinetic parameters and DFT computations for interaction energies.