Dissertations, Theses, and Capstone Projects
Date of Degree
9-2023
Document Type
Dissertation
Degree Name
Ph.D.
Program
Chemistry
Advisor
Michael V. Mirkin
Committee Members
James F. Rusling
Robert J. Messinger
Uri Samuni
Subject Categories
Chemistry
Keywords
electrochemical resistive-pulse sensing, nanoelectrochemistry, intracellular vesicles, extracellular vesicles, single-cell analysis, scanning electrochemical microscopy
Abstract
Electrochemical resistive-pulse (ERP) sensing with conductive carbon nanopipettes (CNPs) is a powerful technique for detecting single nanoscopic entities, such as single liposomes and biological vesicles, enabling qualitative and quantitative analysis of the redox molecules contained in such entities. ERP experiments were first carried out in biological system by inserting a conductive carbon nanopipette into a macrophage cell to sample single vesicles and measuring reactive oxygen and nitrogen species (ROS/RNS) contained inside them.
Besides sensing intracellular vesicles in macrophage cells, we applied this technique to direct detect single extracellular vesicles (EVs) released from a specific cell, and analysis of reactive oxygen and nitrogen species in such EVs. We demonstrated the applicability of ERP sensing to distinguish between non-transformed and cancerous breast cell lines as well as between breast cancer cell lines with different metastatic potential.
Another application of ERP sensing is in real-time monitoring of changes in a normal breast cell induced by a chemical agent. This approach is potentially useful for evaluating the efficacy of therapeutic agents, including those that trigger breast cancer cell death by inducing intense oxidative stress.
To better understand the shapes of ERP current transients by translocations of EVs, we conducted extensive finite-element simulations of an ERP transient. The effects of the pipette geometry, surface charge, transport, vesicle trajectory, and collision location on the shape of current transients were investigated. The possibility of quantitative analysis of experimental ERP transients produced by translocations of liposomes and extracellular vesicles by fitting them to simulated curves was demonstrated.
After a brief introduction to the fundamentals of electrochemical nanosensors and several techniques in Chapter 1, Chapter 2 details carbon nanoprobe fabrication and characterization. In Chapter 3, we applied ERP sensing to detect intracellular vesicles inside a macrophage cell. Then, ERP sensing was employed in real-time monitoring induced oxidation stress in intracellular vesicles in a non-transformed breast cell in Chapter 4. Chapter 5 monitored induced oxidation stress and distinguishes cell types and metastatic cancer lines by ERP sensing of extracellular vesicles. We further conducted simulations of an ERP transient to better understand the shapes of current transients in Chapter 6.
Recommended Citation
Jia, Rui, "Electrochemical Resistive-Pulse Sensing in Biological Systems" (2023). CUNY Academic Works.
https://academicworks.cuny.edu/gc_etds/5490