Rimsha Bhatta

Date of Award


Degree Type

Honors College Thesis


Polymers and High Performance Materials

First Advisor

Jason Azoulay, Ph.D.

Second Advisor

Heather Broadhead, Ph.D.

Advisor Department

Polymers and High Performance Materials


Fluorescent sensors based on conjugated polymers (CPs) have shown promising results in the development of molecular sensing technologies due to their tunable structures, strong fluorescence emission, and high quantum efficiencies. Recent work has demonstrated the potential of CP-based sensors for the detection of pollutants such as azo dyes and polycyclic aromatic hydrocarbons via the inner filter effect (IFE). Most IFE based sensing platforms take place in solution, requiring the accurate measurement of reagents for each test, and precluding the reusability of the assay. To overcome these limitations, a portable and reusable molecular sensing technology has been designed by embedding the CPs into a poly(methyl methacrylate) (PMMA) resin. The spatial separation of the analyte and fluorophore enables the system to be more practical and reusable. In this thesis, we report the optical and thermal characterization of a newly designed sensing platform through thermogravimetric analysis (TGA), and several fluorescence and spectroscopic absorption measurements. The solid state sensor operates through the combination of the IFE and CP-based sensing. The detection limit for a highly absorbing standard, Congo Red, was calculated to be 200 parts-per-billion (ppb), which is lower than the 500-ppb detection limit for the corresponding solution state sensor. Our result confirms that the transition from a solution state sensor to a solid state sensor allows for sensitive detection of dye.

Available for download on Wednesday, August 06, 2223