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Syntheses and Sensing Applications of Modified Noble Metal-containing Nanoparticles

Yu, Zhao
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1623251284619434

Abstract Details

2021, PhD, University of Cincinnati, Arts and Sciences: Chemistry.
Surface-enhanced Raman scattering (SERS), as a promising analytical tool, has been widely used due to the finger-print spectra of the molecular vibrations and the enhancement of signals between hotspots. In this dissertation, different synthesis methods of noble metal-containing nanoparticles have been explored and SERS applications of these nanoparticles in environmental and biological fields have been illustrated. In the first project, trichloroethylene (TCE) in environmental water was determined by SERS quantitatively. Au-core/Ag-shell nanoparticles with 4-mercaptophenylboronic acid (4-MPBA) embedded as internal reference were used as SERS substrates. TCE has little Raman signal, but it can react with 4-mercaptopyridine (4-MPy) through Fujiwara Reaction. 4-MPy was used as the SERS analyte, and the consumption of 4-MPy with the presence of TEC resulted in the intensity change of 4-MPy Raman signal at 1220 cm-1. The 4-MPBA signal at 534 cm-1 was used as an internal reference to normalize 4-MPy signal. The intensity ratio of 4-MPy/4-MPBA linearly decreased when the concentration of TEC increased between 0.2 and 1.0 µM. The detection limit of TCE was 8 ppb and this method was applied to detect TCE in spiked lake water successfully. In the second project, SERS was used as an analytical tool to detect polycyclic aromatic hydrocarbons (PAHs) in environmental soil. ß-cyclodextrin was conjugated to 4-MPBA modified gold nanoparticles to capture and bring the hydrophobic PAHs closer to the surface of gold nanoparticles. Pyrene and anthracene were used as the model PAHs, and 4-MPBA was used as an internal reference. The intensity ratio of pyrene/4-MPBA (580 cm-1/1570 cm-1) was linear in the 2 to 10 nM concentration range and the intensity ratio of anthracene/4-MPBA (750 cm-1/1570 cm-1) was linear in the 10 to 100 nM concentration range. This method was applied to determine pyrene and anthracene in a soil sample and the results had a good recovery when compared to the conventional GC-MS results. In the third project, the detection of single-stranded BRAF V600E mutation DNA showed the feasibility of SERS application in the biological field. Au-coated magnetic nanoparticles with 6-mercaptopyridine-3-carboxylic acid (MPCA) (MNP@SiO2@Au-MPCA) and silver nanoparticles with 4-mercaptobenzonic acid (4-MBA) (Ag@4-MBA) were used as SERS substrates. Rationally designed DNA probes were conjugated to the SERS substrates. With the presence of the single-stranded DNA containing BRAF V600E mutation, it hybridized with the DNA probes and brought the Ag@4-MBA close to the MNP@SiO2@Au-MPCA. The adjunctive DNA probes were ligated under Taqligase through thermal cycles and the resulted nanoparticles were separated easily by a strong magnet. The intensity of the 4-MBA Raman signal indicated the amount of target DNA in the system, and MPCA was used as an internal reference. The intensity ratio of 4-MBA/MPCA was linear in the 1-100 fmol range of the BRAF mutation DNA. Different ratios of BRAF mutation/BRAF normal from 0.02-1% were used to mimic real samples and a good linear regression of the intensity ratio of 4-MBA/MPCA in this range demonstrated the potential for clinical use.
Peng Zhang, Ph.D. (Committee Chair)
Noe Alvarez, Ph.D. (Committee Member)
Hairong Guan, Ph.D. (Committee Member)
Laura Sagle, Ph.D. (Committee Member)
95 p.
Chemistry
Nanoparticles; SERS; Internal reference; Quantitative analysis; Environmental samples; Biological samples

Recommended Citations

Citations

  • Yu, Z. (2021). Syntheses and Sensing Applications of Modified Noble Metal-containing Nanoparticles [Doctoral dissertation, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1623251284619434

    APA Style (7th edition)

  • Yu, Zhao. Syntheses and Sensing Applications of Modified Noble Metal-containing Nanoparticles. 2021. University of Cincinnati, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1623251284619434.

    MLA Style (8th edition)

  • Yu, Zhao. "Syntheses and Sensing Applications of Modified Noble Metal-containing Nanoparticles." Doctoral dissertation, University of Cincinnati, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1623251284619434

    Chicago Manual of Style (17th edition)

ucin1623251284619434
87
© 2020, some rights reserved.Creative Commons License Syntheses and Sensing Applications of Modified Noble Metal-containing Nanoparticles by Zhao Yu is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by University of Cincinnati and OhioLINK.