Analytical Chemistry Research

Analytical Chemistry Research

Andrea Z

Synthesis of a Fluorescence Cu (II) Sensor

Student Researcher: Andrea Zeppuhar
Faculty Advisor: Dr. Maria V. Schiza

This research project investigates the synthesis of a fluorescence copper (II) sensor. This is of importance due to the biological and environmental implications of copper (II) in numerous neurodegenerative diseases and ecological pollution. This sensor depends on an “off-on” system that separates sensing by using two different fluorogenic ligands that are capable of metal chelation. One of the ligands binds to copper (II) while the other produces a fluorescent signal to report the binding. The system contains an equimolar quantity of cadmium (II), and when copper (II) is introduced into the system, cadmium (II) is displaced from one ligand to the other and copper (II) will bind to the ligand that cadmium (II) was originally bound to. This will cause the signal from the copper (II)-ligand 1 to decrease while the signal of cadmium (II)-ligand 2 to increase at the same time, creating an “off-on” system for the detection of the metal of interest. This system can be applied to the synthesis of other metal ion sensors as well.

Taylor K

Synthesis of Variable Size Silver Nanoprisms

Student Researcher: Taylor M. Keller
Faculty Advisor: Dr. Maria V. Schiza

The objective of this project is to synthesize silver nanoprisms with variable size control. Bromide ions will be used for size control because they are known to strongly bind to a silver surface forming silver bromide, which prevents further growth of silver particles. The optical properties of the synthesized nanoprisms will be measured using UV-visible spectroscopy. Further research will be done on the application of these nanoprisms on the enhanced detection of analytes using Raman spectroscopy.

Hellen M

Measurement of oxygen permeability with oxygen sensors based on luminescence quenching

Student Researcher: Hellen Mekonnen
Faculty Advisor: Dr. Jeremiah K.N. Mbindyo

The goal of the study is to develop test strategy for measuring oxygen permeation through packaging materials using oxygen sensors based on luminescence quenching. Oxygen permeation causes shelf- life issues, loss of flavor and discoloration of the packaged product in the food and beverage industry. It also causes reduced shelf life and diminishes effectiveness of packaged pharmaceutical products. Oxygen can penetrate into packages by transmission across the film, through holes, micro- and nanopores or due to inconsistent sealing. Oxygen permeation rates will be measured using OxySense™ and OxyDot™ sensors. The study can lead to the design of packaging materials tailored for specific end use.


ZnS Shell Formation on CdSe Quantum Dots and Ferrocenyl Thiol Ligand Attachment for Biocompatible Imaging and Sensing Probes

Student Researcher: Lisa Nguyen
Faculty Advisor: Dr. Maria V. Schiza

The objective of this research project is to coat Cadmium Selenide (CdSe) quantum dots with a Zinc Sulfide (ZnS) shell and to attach various ligands to make the inorganic nanoparticles compatible with biosensing technologies. CdSe/ZnS quantum dots can be very useful to biomedical imaging because they have a broad excitation range and narrow emission spectra. These characteristics make triggering and detecting the quantum dots fairly easy. These quantum dots have the potential to produce high-resolution cellular imaging on the single-molecular level. This technique will aide in the detection of cancer tumors. The imaging and sensing techniques produced from cadmium complexes will exhibit more photo stability than their organic counterparts because they do not undergo photobleaching. CdSe/ZnS quantum dots will have many possible applications in both the biomedical and environmental fields. This research project will focus on the biocompatible properties as CdSe/ZnS quantum dots are attached with organic and inorganic ligands. By studying these nanoparticles, we can help find solutions for the problems we face in our modern society.