Related Experiment Video
Updated: Mar 13, 2026
Chemiluminescence-based Assays for Detection of Nitric Oxide and its Derivatives from Autoxidation and Nitrosated Compounds
Published on: February 16, 2022
Colorimetric analysis of the decomposition of S-nitrosothiols on paper-based microfluidic devices
Abdulghani Ismail1, Marillya O Araújo2, Cyro L S Chagas2
1Instituto de Química, Universidade Federal de Goiás, Campus Samambaia, Goiânia, GO 74690-900, Brazil. wendell@ufg.br and Chimie ParisTech, PSL Research University Unité de Technologies Chimiques et Biologiques pour la Santé, 75005 Paris, France and INSERM, Unité de Technologies Chimiques et Biologiques pour la Santé (no. 1022), 75005, Paris, France and CNRS, Unité de Technologies Chimiques et Biologiques pour la santé UMR 8258, 75005 Paris, France and Université Paris Descartes, Sorbonne Paris Cité, Unité de Technologies Chimiques et Biologiques pour la Santé, 75005 Paris, France.
Abstract:
A disposable microfluidic paper-based analytical device (μPAD) was developed to easily analyse different S-nitrosothiols (RSNOs) through colorimetric measurements. RSNOs are carriers of nitric oxide (NO) that play several physiological and physiopathological roles. The quantification of RSNOs relies on their decomposition using several protocols and the colorimetric detection of the final product, NO or nitrite. μPADs were fabricated by wax printing technology in a geometry containing one central zone for the sample inlet and eight circular detection zones interconnected by microfluidic channels for decomposition and posterior detection of decayed products. Different decomposition protocols including mercuric ions and light (UV, visible, and infrared) were tested on μPADs. For this purpose, a 3D printed holder was coupled with μPADs to easily design a simultaneous decomposition procedure using different light sources. The Griess reagent was added to detect NO and nitrite produced by the different decomposition methods. μPADs were then scanned using a flat board scanner and calibration curves based on color intensity were plotted. The limit of detection (LOD) values achieved for nitrite (used as a reference compound) and S-nitrosoglutathione (GSNO) using mercuric decomposition were 3 and 4 μM, respectively. The LOD reported herein for nitrite is considered among the lowest LODs already reported for this compound using μPADs. The results also show that low-molecular-weight RSNO, namely S-nitrosocysteine, decomposes more easily than high-molecular-weight RSNOs with light. As a proof of concept, RSNOs in human plasma were successfully detected on μPADs. For this purpose, a preliminary treatment step was optimized and the presence of high-molecular-weight (HMW) RSNOs was evidenced in the available plasma samples. The concentrations of HMW-RSNOs and nitrite in the various samples ranged from 5 to 16 μM and from 37 to 58 μM, respectively.
