Date of Award
Spring 2026
Language
English
Embargo Period
4-24-2027
Document Type
Master's Thesis
Degree Name
Master of Science (MS)
College/School/Department
Department of Chemistry
Program
Chemistry
First Advisor
Mehmet Yigit
Committee Members
Jia Sheng, Alexander Shekhtman
Keywords
Fluorescence, CRISPR-Cas12a, Nanotechnology, Nanoparticle, DNA, Biosensor
Subject Categories
Analytical Chemistry | Biophysics
Abstract
DNA-templated silver nanoclusters have regained significant attention due to recent advances in stability and control over their optical behavior. Here, we report a highly regulated DNA-templated silver nanocluster platform (DFN2) that exhibits strong fluorescence emission at 561 nm and enables reversible, label-free fluorescence switching governed by nucleic acid hybridization. The intrinsic fluorescence of DFN2 is efficiently quenched upon hybridization with complementary DNA or RNA strands and fully restored through invading RNA strand–mediated displacement, enabling robust and programmable ON-OFF-ON optical control. We integrated this hybridization-responsive platform with CRISPR-Cas12a to construct a target-activated biosensing system. Upon sequence-specific recognition of a conserved genomic fragment from the model foodborne pathogen Listeria monocytogenes, the activated Cas12a cleaves a regulator DNA strand, initiating a cascade of hybridization and strand displacement reactions that restore nanocluster fluorescence though an invasive RNA. This strategy enables amplification-free detection and exhibits high specificity against conserved genomic regions from other tested foodborne pathogens. Overall, this work establishes DNA-templated silver nanoclusters as programmable, enzyme-responsive optical reporters and introduces a dynamic RNA-regulated platform that enables a modular, label-free approach for rapid and sensitive point-of-care biosensing.
License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License
Recommended Citation
Gold, Reggie E., "Fluorescently Quenched Silver Nanoclusters for Detection of Food-Borne Pathogens" (2026). Electronic Theses & Dissertations (2024 - present). 395.
https://scholarsarchive.library.albany.edu/etd/395