Characterizing and Optimizing the Synthesis of 'bubble' Dna-templated Silver Nanoclusters as a Fluorescent Material
Open Access
Author:
Campbell, Ian Edward
Area of Honors:
Chemistry
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
Bruce Paul Wittmershaus, Thesis Supervisor Alan John Jircitano, Thesis Honors Advisor Darren Williams, Faculty Reader
Keywords:
DNA templated silver nanoclusters fluorescent optimize synthesis stability chemical yield
Abstract:
A new format of DNA-templated silver nanoclusters (AgNCs) has been synthesized by hybridizing the strands 5’- CTGACTCCCnTGGGAGAA -3’ and 5’- TTCTCCCACnGGAGTCAG -3’ with n=2, 3, 4, 5, 6, 7, 8, 10, 12, and 16 cytosine pairs in water and phosphate buffer (pH=7). Fluorescent populations emitting at ~545nm and ~630nm and absorbing at ~470nm and ~570nm, respectively, were formed from each bubble template. The bubble template with 8 cytosine pairs formed the brightest ~630nm emitter, while the 7 cytosine pair template formed the brightest ~545nm emitter. The template with 8 cytosine pairs formed the most stable AgNCs with the ~545nm emission increasing over the course of 116 hours and the ~630nm emission reaching ~16% its maximum value after 116 hours. Preliminary optimized Ag:NaBH4:DNA was found to be 14:14:1. Single stranded bubble templates were found to be much less stable than hybridized bubble templates. Finally, optimal phosphate buffer (pH=7) concentration, DNA concentration, silver-to-DNA ratio, and silver-to-sodium borohydride ratio were found to be 7.88μM, 10μM, 11.25, and 2.20, respectively, via Box-Behnken experimental design with chemical yield and photostability as response factors.
