Performing Reliable Absorbance and Fluorescence Measurements With Low Budget – A Tutorial for Beginners

Abstract

Molecular absorbance and fluorescence measurements are usually performed by benchtop or portable USB spectrophotometers or fluorometers. However, even the simplest configuration of these instruments requires considerable financial input, which is not affordable to many universities and research groups especially when public politics withdraw funds from science. Light-emitting diodes (LEDs) based devices can be an interesting alternative for low-cost, portable yet reliable measurements of absorbance of fluorescence. Especially if associated with the fabrication of 3D structures by additive manufacturing techniques. Although there are many reviews in the literature dedicated to discussing the theoretical aspects and analytical performance of LED-based devices, we consider that these reviews are not easily applicable for beginners in electronics. It results in the intimidation to employ such powerful tools which could have a huge impact mainly to small and/or initial groups. In this tutorial, we present a guide that will help students and researchers to construct “lab-built” devices based on simple optoelectronic components and 3D printing to perform molecular absorbance and fluorescence measurements for analytical methods. Finally, with this tutorial guide, we anticipate a large spread of the usage of LED devices for reliable analytical measurements that can be extensively used in many scenarios.

Fabrication of Low-Cost Miniaturized Gas Cells via SLA 3D-Printing for UV-Based Gas Sensors

“…The development of an iHWG for the ultraviolet (UV) range represents a challenging but promising opportunity, especially for gas-sensing applications. , The UV spectrum covers a broad spectrum of gaseous molecules that exhibit pronounced absorption characteristics in the 190–400 nm range, which includes specific hydrocarbons, volatile organic compounds, and certain atmospheric pollutants. Accordingly, optical sensors operating in the UV range have the potential to offer fast response times, suitable sensitivity, and minimal cross-reactivity with other substances. − …”