Photo, Thermal, and Temporal Stability of Protein-Templated Fluorescent Gold Nanoclusters
Abstract
Biotemplated fluorescent gold nanoclusters (AuNCs) have received a great deal of attention due to their ultra-small size, biocompatibility, and tunable fluorescent properties. Of particular interest are protein-templated gold nanoclusters (P-AuNCs), many of which have been shown to combine the photophysical properties of AuNCs as well as the native bioactivity of proteins. Although there is substantial research on the synthesis of biostabilized AuNCs, there are few reports on the photostability and thermal stability of these AuNCs. This report examines the photostability and thermal stability of bioconjugated P-AuNCs using two different protein templates: bovine serum albumin (BSA) and pepsin. The red-emitting BSA-AuNCs and the green-emitting pepsin-AuNCs exhibited resistance to photobleaching under continuous UV irradiation ( = 365 nm) for up to 24 h; the blue-emitting pepsin-AuNCs were nearly twofold less photostable. Interestingly, the blue-emitting NCs exhibited the greatest thermal stability, retaining approximately 80 of their initial fluorescence intensity after 30-min incubation at 80 C, while the BSA-AuNCs retained approximately 30 of their initial fluorescence, and the pepsin-AuNCs lost all fluorescence due to protein precipitation out of solution. All three synthesized P-AuNCs exhibited minimal loss (less than 10 ) in fluorescence intensity for a period of up to 6 months when stored at 4 C. These results suggest the robustness and enhanced thermal and photostability of P-AuNCs, making them highly attractive for a wide range of optoelectronics, sensing, and imaging applications.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 12, 2018
- Accession Number
- AD1060422
Entities
People
- Andres A. Bujanda
- Joseph R Palmeri
- Lily Giri
- Sasha Teymorian
- Shashi P. Karna
Organizations
- United States Army Research Laboratory