Date of Graduation

Spring 2024


Master of Natural and Applied Science in Biology



Committee Chair

Kyoungtae Kim


Fluorescent nanoparticles known as quantum dots (QDs) have unique properties that make them useful in biomedicine. Specifically, CdSe/ZnS QDs, while good at fluorescing, show toxicity. Due to this, safer alternatives have been developed. This study uses an XTT viability assay, ROS fluorescent imaging, and apoptosis to investigate the effect of QD alternatives InP/ZnS, CuInS2/ZnS, and carbon dots (NCD) in liver cells. The liver is a possible destination for accumulation of QDs making it an appropriate model for testing. A cancerous liver cell line known as HepG2, and an immortalized liver cell line known as THLE-2 were used. At a nanomolar range of 10-150, HepG2 cells demonstrated no reduced cell viability after 24 hrs. The XTT viability assay demonstrated that CdSe/ZnS and CuInS2/ZnS show reduced cell viability in THLE-2 cells with concentrations between 50-150nM. Furthermore, CdSe/ZnS and CuInS2/ZnS treated THLE-2 cells generated ROS as early as 6 hrs after treatment and elevated apoptosis after 24 hrs. To further corroborate our results, apoptosis assays revealed an increased percentage of cells in the early stages of apoptosis for CdSe/ZnS (52%) and CuInS2/ZnS (38%) treated THLE-2. RNA transcriptomics reveal heavy downregulation of cell adhesion pathways such as wnt, cadherin, and integrin in all QDs except carbon dots. In conclusion, carbon dots show the least toxicity toward these two liver cell lines. While demonstrating less toxicity than CdSe/ZnS, the metallic QDs (InP/ZnS and CuInS2/ZnS) still demonstrate potential concerns to liver cells. This study serves to explore the toxicity of QD alternatives and better understand their cellular interactions.


quantum dots, CdSe/ZnS, InP/ZnS, CuInS2/ZnS, NCD, XTT viability assay, ROS assay, apoptosis assay, transcriptomics

Subject Categories

Cancer Biology | Cell Biology | Nanotechnology | Structural Biology | Toxicology


© Seth Harris

Available for download on Thursday, May 01, 2025

Open Access