Sensing platforms based on polymeric microsphere ion selective bulk optodes
Abstract
Recent advancements in new materials, fabrication techniques, and characterization methods have motivated research on chemical sensors and biosensors with high sensitivity, reversibility and cost-efficiency. Ion-selective bulk optodes are a unique class for measuring the ion activities instead of total concentrations. Originally derived from the sensing principles of ion-selective electrodes, bulk optodes work on the competitive or collaborated extraction of two ions into the organic phase containing sensing ingredients. Because of the two-phase sensing mechanism, high sensitivity of the optical readout and the small sizes, the detection limits of bulk optodes promise to reach the true lower detection limit predicted by thermodynamics. The ultimate goal of this research is to develop a total optical sensing system that has great advantage for high-throughput analysis of multiple analytes based on ion selective bulk optode microsphere sensors. A systematic study involving bulk optode thin films and microspheres was performed on tuning the sensing range, fabrication methods for microsphere bulk optodes, and the application of bulk optode microspheres in environmental trace analysis as well as determination of blood electrolytes in real physiological samples. The fabricated microspheres were mounted on imaging fiber bundles, or coupled with analytical flow cytometry for array based sensing or the simultaneous readout of three common blood electrolytes in one sample with microsphere bulk optodes that were generated from the same chromoionophore. In another work that aimed at multiplexed fluorescent microsphere based assays, the solvent casting method was used to prepare multicolor-encoded polymeric microspheres with quantum dots, followed by testing their functionality in an ion sensing system.
Degree
Ph.D.
Advisors
Bakker, Purdue University.
Subject Area
Analytical chemistry|Health sciences|Environmental science
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