Portable Instrument for Monitoring Environmental Toxins Using Immobilized Quantum Dots as the Sensing Material
Open Access
- 7 May 2020
- journal article
- research article
- Published by MDPI AG in Applied Sciences
- Vol. 10 (9), 3246
- https://doi.org/10.3390/app10093246
Abstract
A portable instrumental system was designed for the routine environmental monitoring of toxic volatile organic compounds (VOCs) in atmospheric conditions based on changes in the photoluminescence emission of semiconductor nanoparticles (quantum dots) entrapped in a sol-gel matrix as the solid sensing material. The sol-gel sensing material displayed a long-lived phosphorescent emission, which is quenched in the presence of trace levels of a volatile organic compound (acetone) in gaseous atmospheres. The developed instrument could measure and process the changes in the photoluminescence of the sensing material after exposure to gaseous acetone. The developed prototype device consists of a deep-ultraviolet ligtht-emitting diode (UV LED), which excites the chemical sensing material; an optical filter to remove scattered light and other non-desirable wavelengths; a photomultiplier tube (PMT) to convert the phosphorescence emission of the sensor phase to an electrical signal; and a microcontroller to correlate the signal with the analyte concentration. The developed prototype was evaluated for its ability to measure low levels of gaseous acetone in contaminated atmospheres with high sensitivity (detection limit: 9 ppm). The obtained results show the feasibility of this type of instrument for environmental analytical control purposes.This publication has 31 references indexed in Scilit:
- Portable Fluorometer for Cyanobacteria DetectionIEEE Sensors Journal, 2017
- A study of global atmospheric budget and distribution of acetone using global atmospheric model STOCHEM-CRIAtmospheric Environment, 2015
- Optical gas sensing: a reviewMeasurement Science and Technology, 2012
- Mn-doped ZnS quantum dots for the determination of acetone by phosphorescence attenuationAnalytica Chimica Acta, 2012
- A portable fluorescence detector for fast ultra trace detection of explosive vaporsReview of Scientific Instruments, 2011
- Luminescence in colloidal Mn2+-doped semiconductor nanocrystalsJournal of Solid State Chemistry, 2008
- The use of luminescent quantum dots for optical sensingTrAC Trends in Analytical Chemistry, 2006
- A Review of Heavy-Atom-Induced Room-Temperature Phosphorescence: a Straightforward Phosphorimetric MethodCritical Reviews in Analytical Chemistry, 2005
- Semiconductor Clusters, Nanocrystals, and Quantum DotsScience, 1996
- Synthesis and characterization of nearly monodisperse CdE (E = sulfur, selenium, tellurium) semiconductor nanocrystallitesJournal of the American Chemical Society, 1993