Synthesis and application of luminescent silver nanodot
Silver nanodots have been successfully encapsulated in dendrimers, microgels, and peptides, the single stranded DNA (ssDNA), resulting in water-soluble fluorophores. Many applications have been published as probes,
photoluminescent materials, electroluminescent materials and
Peptides stablized silver nanodots
Argyrophilic proteins are good templates for the generation of silver nanodots. Photoactivation of a silver ion loaded cells creates luminescent silver nanodots (A). These nanodots are quite photostable, with a low photobleaching rate after a faster decay in emission intensity at the beginning (B). Even though the argyrophilic proteins, such as nucleolin, protect silver nanodots well, the size of such proteins exceeds 600 amino acid residues. However, an 18 residue peptide inspired by nucleolin produces silver nanodots with similar photophysical properties but much smaller size (C). The peptide-protected silver nanodots show red emission with large Stokes shift (D).
Cellular Staining By Silver Nanodot Transfer
A cartoon illustrates that luminescent silver nanodots are transferred from a low molecular weight shuttle (PA) to a single-stranded DNA, C12. BPAECs stained with anti-actin-C12 conjugate and visualized by silver nanodot transfer. Colocalization (C) of emission images of BPAEC from silver nanodots (D) and FITC (B) tagged to anti-actin-C12 to indicate the location of actin.
Excellent photostability of silver naodots under either one-photon excitation or two-photon excitation
Imaging and photo-stability of C20 silver nanodots (green) in NIH 3T3 cells co-labeled with HCS red cell stain (red) under one photon excitation (OPE, 458 nm, A) or two photon excitation (TPE, 720 nm, B). The photostability can be easily seen by the color decay of images in nuclei (green C20 silver nanodots) and cytoplasm (HCS red cell stain), and illustrated in C (for OPE) and D (for TPE) by their mean luminescence intensity of individual emitters in the corresponding scanning images. The green Ag nanodots show similar photostability to HCS red cell stain under OPE, but much greater stability under TPE.