Document Type
Thesis
Date of Award
2026
Degree Name
Master of Science (MS)
Department
Chemistry
First Advisor
Steven Wu
Abstract
Heavy metals, such as Hg, Cd, Pb, and Cr, become a serious environmental problem because they are highly toxic, bioaccumulation, and long-term persistence, required a high sensitivity and selectivity detection method. Although laboratory testing instruments, such as inductively coupled plasma mass spectrometry, offer high sensitivity, their practical application is limited because they rely on large-scale equipment and complex sample pre-treatment processes. Single-emission fluorescence probes are simpler but can be affected by variations in probe concentration, excitation intensity, and measurement conditions. In this study, a dual-emission nanohybrid that consists of poly(9,9-di-n-hexylfluorenyl-2,7-diyl) (PDHF) and bovine serum albumin (BSA), termed as PDHF-Pdots/BSA-AuNCs nanohybrid, was prepared through a modified nanoprecipitation method, for the detection of mercury ions. The PDHF-Pdots provided a comparatively stable reference emission, while the emission from the bovine serum albumin (BSA)-AuNCs decreased in response to Hg²⁺. The nanohybrid concentration, reaction time, and pH of PBS buffer were optimized to obtain a measurable and reproducible response. The fluorescence intensity ratio (I620/I420) decreased as the Hg²⁺ concentration increased, supporting the use of the nanohybrid for ratiometric detection. The probe also responded more strongly to Hg²⁺ than to the other metal ions tested individually. These findings demonstrate the feasibility of combining PDHF-Pdots and BSA-AuNCs as a rapid, internally referenced fluorescence platform for Hg²⁺ detection. Further refinement is needed to improve sensitivity and evaluate the probe in mixed-ion systems and real water samples.
Subject Categories
Chemistry
Keywords
Not Given
Number of Pages
44
Publisher
University of South Dakota
Recommended Citation
Wu, Sha, "A DUAL-EMISSION POLYMER-DOTS/GOLD-NANOCLUSTERS NANOHYBRID FOR RATIOMETRIC FLUORESCENCE DETECTION OF Hg²⁺" (2026). Dissertations and Theses. 433.
https://red.library.usd.edu/diss-thesis/433