Toronto Metropolitan University
Agarwal, Ayushi.pdf (12.87 MB)
Download file

Quantum Scale Plasmonic Material for Biomedical Applications

Download (12.87 MB)
posted on 2022-05-25, 20:42 authored by Ayushi Agarwal

Here physically synthesized (non-chemically engineered) gold quantum particles were investigated to study the structural behavior of genomic DNA towards gold particles in the microcellular environment for sensing, diagnosis, and therapeutics nanomedicine application. The non-conformational changes in genomic DNA were witnessed for three different cell types: lung cancer cells (H69), pancreatic cancer cells (ASPC-1), and healthy fibroblast cells (NIH 3T3). By the intracellular chemical analysis of gold quantum particles, results show that the gold quantum particles remain in their native chemical state (Au (0)) after internalizing inside the nucleus, and do not undergo a redox reaction in the cellular environment which leads to the low affinity of gold ions towards the cellular components. The physically synthesized native gold quantum particles do not fluctuate the sodium concentration inside the nucleus which is known to impact the stability of the genomic DNA structure directly. In contrast to commonly used gold particles the ultrafast laser synthesized (physically engineered) quantum size native gold particles can be internalized inside the cells as well as the nucleus without causing any conformational changes in secondary genomic DNA structure. Additionally, label-free gold quantum particles were used for cancer sensing to provide the opportunity to attain the sensing of oncoprotein and nuclear components instantaneously. Since the gold quantum particles are non- toxic, no layering is required, enabling the study of the exact quantum effect in plasmonic cellular signaling. The naked gold quantum particles confirmed self-cellular uptake with even  iv  distribution and non-specific attachment to all the cellular components. The gold quantum particle size is found to be inversely related to the signal strength of the plasmonic readout. The gold quantum particles provide a holistic picture of cell states and may open up new possibilities for accurate SERS diagnosis of cancer. Adding to this the concept of small-sized self- functionalized pristine also introduced gold quantum particles for cancer theranostics. The pristine gold quantum particles demonstrated cancer-selective cell uptake enabling dosage- dependent fluorescent detection/differentiation of cancerous cells and cancer-selective cytotoxicity. The fabricated gold quantum particles demonstrated fluorophore-free fluorescence illuminance at a broad range of  excitation wavelengths and drug-free cancer-specific treatment. According to this study the as- fabricated gold quantum particles have dual functions of fluorescent diagnosis and treatment of  cancerous cells. Moreover the drug-free gold quantum particles may find advantages in fighting drug-resistant cancers. Here the current research opens a frontier for the future of gold-based nanomedicine and its application for sensing, diagnosis, and therapeutics in in vitro environment.





  • Doctor of Philosophy


  • Mechanical and Industrial Engineering

Granting Institution

Ryerson University

LAC Thesis Type

  • Dissertation

Thesis Advisor

Krishnan Venkatakrishnan Bo Tan