Date of Award
12-1-2025
Degree Name
Doctor of Philosophy
Department
Chemistry
First Advisor
Shamsi, Mohtashim
Abstract
Electrochemical biosensing based on the adsorption of nucleic acids onto two-dimensional (2D) nanomaterials offers distinct advantages over conventional techniques, including enhanced sensitivity, selectivity, and simplified probe immobilization. Significant efforts have been directed toward developing sensing platforms that exploit the high surface area and unique physicochemical properties of materials such as graphene oxide (GO) and molybdenum disulfide (MoS₂) to achieve efficient signal transduction. This adsorption-based approach eliminates the need for complex surface modifications or labeling, as nucleic acids interact with 2D surfaces through π–π stacking, van der Waals forces, hydrogen bonding, electrostatic interactions, and ion bridging.The efficiency of nucleic acid immobilization depends on factors such as ionic strength, pH, incubation time, and probe concentration. Under neutral conditions, the negative charges on both the nanomaterials and nucleic acids lead to electrostatic repulsion. To overcome this, metal ions are introduced to screen the charges, thereby enhancing probe adsorption onto the nanomaterial surface. Traditional electrochemical chips are generally limited to detecting a single analyte. In contrast, multiplexed platforms enable the simultaneous detection of multiple targets from a single sample. Wax-on-plastic multiplex devices—fabricated using low-cost and accessible techniques such as inkjet and wax printing—offer additional advantages, including ease of fabrication, fast response, and mechanical flexibility.
Access
This dissertation is Open Access and may be downloaded by anyone.