Highly Sensitive Colorimetric Assay for Determining Fe³⁺ Based on Gold Nanoparticles Conjugated with Glycol Chitosan

Figure 1

(a) UV-Vis absorption spectra of (1) AuNPs, (2) GC-AuNPs, and (3) GC-AuNPs conjugated with Fe³⁺. (b) 3D-AFM image (left), TEM image (middle), and the corresponding particle size distribution histogram of GC-AuNPs (right). (c) 3D-AFM image (left), TEM image (middle), and particle size distribution histogram of GC-AuNPs conjugated with Fe³⁺ (right). AuNPs, gold nanoparticles; GC-AuNPs, gold nanoparticles conjugated with GC.

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