Fig. 2

Characterization of AuNPs and the AuNP-mAb probe. (a) Transmission electron microscopy (TEM) images of AuNPs with scale bars of 20 nm. (b) The color of the colloidal gold solution with different volumes of K₂CO₃. (c) UV‒Vis absorption spectra of the AuNPs and the AuNP-mAb probe. (d) The zeta potentials of the AuNPs and the AuNP-mAb probe