ERIC Number: EJ1062228
Record Type: Journal
Publication Date: 2015-Feb
Abstractor: As Provided
Reference Count: 20
"Open-Box" Approach to Measuring Fluorescence Quenching Using an iPad Screen and Digital SLR Camera
Koenig, Michael H.; Yi, Eun P.; Sandridge, Matthew J.; Mathew, Alexander S.; Demas, James N.
Journal of Chemical Education, v92 n2 p310-316 Feb 2015
Fluorescence quenching is an analytical technique and a common undergraduate laboratory exercise. Unfortunately, a typical quenching experiment requires the use of an expensive fluorometer that measures the relative fluorescence intensity of a single sample in a closed compartment unseen by the experimenter. To overcome these shortcomings, we designed an "open-box" fluorescence quenching method that uses an iPad screen as the excitation source and a digital single-lens reflex (SLR) camera as the detector. This setup enables a complete fluorescence quenching experiment to be performed and an accurate Stern-Volmer plot to be generated by analyzing a single image of six fluorescein samples and applying correction factors. The Stern-Volmer quenching constant (K[subscript SV]) calculated using this method was 9.62 ± 0.27 L mol[superscript -1]; fluorometer value, 9.52 ± 0.40 L mol[superscript -1]; literature values, 9.0 ± 0.2 L mol[superscript -1] and 9.608 L mol[superscript -1]. These results demonstrate that, in addition to allowing direct visualization of the chemical processes and simultaneous measurement of multiple samples, this simple method yields quantitative results comparable in accuracy to the more expensive fluorometer.
Descriptors: Light, Science Instruction, College Science, Undergraduate Study, Science Laboratories, Science Experiments, Laboratory Experiments, Educational Technology, Handheld Devices, Laboratory Equipment, Chemistry, Scientific Concepts, Spectroscopy, Kinetics, Technology Uses in Education, Measurement Techniques
Division of Chemical Education, Inc and ACS Publications Division of the American Chemical Society. 1155 Sixteenth Street NW, Washington, DC 20036. Tel: 800-227-5558; Tel: 202-872-4600; e-mail: firstname.lastname@example.org; Web site: http://pubs.acs.org/jchemeduc
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Higher Education; Postsecondary Education
Authoring Institution: N/A