Monoclonal-Antibody-Templated Gold Nanoclusters for HER2 Receptors Targeted Fluorescence Imaging.

HER2 receptor-specific monoclonal-antibody-templated gold nanoclusters, Herceptin-templated Au NCs (Her-Au NCs), have been successfully obtained via "green" synthesis. This strategy allows the fluorescent gold nanoclusters (Au NCs) formed in the three-dimensional structure of Herceptin without destroying the high specificity and affinity to HER2 receptors. The Her-Au NCs have been found to be superior compared to Cy3-Herceptin in the fluorescence emission (λ em = 645 nm) and the photostability under high-intensity UV irradiation or long-time storage. Moreover, Her-Au NCs can achieve receptor-specific imaging without targeted modification owing to the HER2-binding ability of the Herceptin scaffold. For imaging applications, Her-Au NCs can be utilized as effective optical probes for not only fluorescence imaging of HER2-positive cancer cells but also imaging of HER2-positive tumors in vivo.