A 96-well microplate kit coated with an anti-AFP-L3 antibody (AFP (H-9):sc-166335, Santa Cruz Biotechnology, Inc.) was used to immobilize AFP-L3 in test samples. In a typical assay, 50 μL of test sample was immobilized on the kit according to manufacturer’s instruction, followed by addition of 100 μL of Man-AuNP@LcA. Then kit was shaken for 10 min, and the optical absorbance of each well was measured at 525 nm using a microplate reader. Standards of defined concentrations were run in each assay, allowing for the construction of a calibration curve by plotting absorbance versus concentration. The AFP-L3 glycoprotein concentrations in the sample were then calculated from this calibration curve.