Iodide-Mediated Etching of Gold Nanostar for the Multicolor Visual Detection of Hydrogen Peroxide

A multicolor visual method for the detection of hydrogen peroxide (H(2)O(2)) was reported based on the iodide-mediated surface etching of gold nanostar (AuNS). First, AuNS was prepared by a seed-mediated method in a HEPES buffer. AuNS shows two different LSPR absorbance bands at 736 nm and 550 nm, respectively. Multicolor was generated by iodide-mediated surface etching of AuNS in the presence of H(2)O(2). Under the optimized conditions, the absorption peak Δλ had a good linear relationship with the concentration of H(2)O(2) with a linear range from 0.67~66.67 μmol L(−1), and the detection limit is 0.44 μmol L(−1). It can be used to detect residual H(2)O(2) in tap water samples. This method offered a promising visual method for point-of-care testing of H(2)O(2)-related biomarkers.