“…Colorimetric detections are convenient and effective in many applications because the readout requires only human eyes, without the aid of any sophisticated instruments. In the last few decades, plasmonic nanoparticles, especially Au nanoparticles (AuNPs), have attracted much attention as an ideal transducer of colorimetry for sensing, recognizing, and determination of ions and small biomolecules, 20–24 because the aggregation of solutions with low concentrations of AuNPs displays a clear color change. The detection of OCl − can also use AuNP-based colorimetric methods.…”