Document Type
Dissertation
Date of Award
2024
Degree Name
Doctor of Philosophy (PhD)
Department
Chemistry
First Advisor
Steven SW Wu
Abstract
Biosensors have been deeply valued and widely used in fermentation technology, environmental monitoring, food engineering, clinical medicine, and the military. However, current biosensors still face many technical challenges, such as miniaturization, convenience, high precision, and low power consumption which restrict the popularization and development of biosensors. Meeting these challenges require the development of advanced materials and technologies. Optical biosensors offer distinct advantages such as high sensitivity, rapid response time, and the potential for miniaturization, making them ideal for overcoming the existing limitations. My research in this dissertation explores the development and application of advanced functional nanomaterials in optical biosensing, focusing on temperature, L-lactate, pH and glucose detection. The research is divided into two main objectives: semiconductor polymer dots (Pdots) based ratiometric fluorescence biosensors and nanozyme-based biosensors. In the first objective, a highly sensitive L-lactate detection method was developed using Pdots-Pt combined with an enzyme cascade reaction to amplify the signal, which achieving a detection limit of 0.18 nM and demonstrating the potential of clinical diagnosis. Additionally, a Pdots-Eu based ratiometric fluorescent nanothermometer was created for precise in vitro temperature sensing, showing a linear response from 25°C to 50°C. The second objective introduced iron-doped silicon nanoparticles (Fe-Si NPs) synthesized via a one-pot hydrothermal method, exhibiting high peroxidase-mimetic catalytic activity. These Fe-Si NPs, as nanozymes, were effectively used for glucose sensing and intracellular pH monitoring, showing excellent stability, sensitivity, and selectivity. The results provide innovative solutions for sensitive and selective detection of key biomarkers, contributing to the advancement of biosensing technology. Future work aims to integrate these biosensing systems into portable devices, explore other biomarkers, transition to in vivo applications, and advance commercialization efforts. In summary, our study highlights the potential of functional nanomaterials to revolutionize biosensing, providing new diagnostic and therapeutic opportunities in healthcare.
Subject Categories
Chemistry
Keywords
biosensor, nanozyme, semiconducting polymer dots
Number of Pages
118
Publisher
University of South Dakota
Recommended Citation
He, Shuyi, "ADVANCED OPTICAL BIOSENSING USING RATIOMETRIC FLUORESCENT POLYMER DOTS AND NANOZYME" (2024). Dissertations and Theses. 233.
https://red.library.usd.edu/diss-thesis/233