Glowing-in-the-Screen: Teaching Fluorescence with a Homemade Accessible Setup

Abstract

Teaching fluorescence aims to deeply communicate light–matter interactions. The main fluorescence concepts are covered in undergraduate courses and are difficult to comprehend as the proper lighting conditions for seeing it by the naked eye are rarely found in daily life. Here, we present a lab activity to explore fluorescence using homemade equipment in order to complement the teaching of the basics of fluorescence and perform typical experiments. This device consists of a cardboard box as fluorometer with a flashlight as an excitation source and a smartphone camera with an application for color analysis as a detector. The presented assays can be used in diverse teaching environments to reinforce the universal concepts of fluorescence, Stokes shifts, quenching, and the inner filter effect. The assays are based on common products (such as green leaves, turmeric, tonic water, and salt), so access to the materials and waste generation are not a problem. The results, robustness, and reliability of this setup were discussed after evaluating the comments of teachers and students who perform the lab experiences. Furthermore, the performance of the students was assessed using a survey, which demonstrates this is an excellent approach to increase their interest and motivation for learning.

At-Home Laboratory Experiments for the Analytical Chemistry Curriculum

“…Moreover, many instrumental analysis courses introduce students to the concepts of static and dynamic fluorescence quenching, yet students’ visual understanding of these phenomena is often reduced to observing a decreased fluorescence signal on a computer that is connected to a spectrometer. It has been previously noted in the literature that undergraduate laboratories that focus on visualization of fluorescence and fluorescence quenching lead to increased student enthusiasm and improved conceptual understanding. , Thus, we have developed a quick, simple demonstration of fluorescence quenching that can be performed at home (or in the classroom) using affordable and easily accessible materials.…”

A Gentle Introduction to Machine Learning for Chemists: An Undergraduate Workshop Using Python Notebooks for Visualization, Data Processing, Analysis, and Modeling

“…It is worth mentioning that this workshop was entirely online due to the social isolation during the COVID-19 pandemic and it did not present any complications. Therefore, it could be an excellent complement for laboratory experiments at home …”

Optical Chemical Sensing of Iodide Ions: A Comprehensive Review for the Synthetic Strategies of Iodide Sensing Probes, Challenges, and Future Aspects

“…Scheme 20. Synthesis scheme of conjugated polymers (30)(31)(32)(33) for sensing of iodide ions. Scheme 21.…”

“…During the second half of 20 th century, various organic dyes had also been utilized for optical chemosensing of halide ions in water including quinine, 6‐methoxyquinoline, anthracene, coumarin, rhodamine, fluorescein, and heterocyclic aromatic compounds by collision‐induced quenching processes [32–35] . But these dyes had certain drawbacks, such as a lower limit of detection of halide ions in the millimolar concentration range, lower selectivity, interference of pseudohalides, heavy atoms containing molecules that limited their practical applications [36] .…”