Smartphone-assisted detection of monocrotophos pesticide using a portable nano-enabled chromagrid-lightbox system towards point-of-care application.

With the aim of monocrotophos pesticides detection in environmental and food samples at point-of-care (PoC) application, this research, for the first time, explores silica alcogel as an immobilization matrix to support the development of in-house customized nano-enabled "chromagrid-lighbox" as a sensing system. This system is fabricated using laboratory waste materials and demonstrates the detection of highly hazardous monocrotophos pesticide using a smartphone. Nano-enabled chromagrid is a chip-like assembly filled with silica alcogel -a nanomaterial (hence the name "nano-enabled" chromagrid), and "chromogenic reagents" which is required for the enzymatic detection of monocrotophos. Lightbox is the imaging station fabricated to provide constant lighting conditions to the chromagrid to capture accurate colorimetric data. The silica alcogel used in this system was synthesized from Tetraethyl orthosilicate (TEOS) via a sol-gel method and characterized using advanced analytical techniques. Further, three chromagrid assays were developed for the optical detection of monocrotophos with a low detection limit (LOD) at 0.421 ng ml (by α-NAc chromagrid assay), 0.493 ng ml (by DTNB chromagrid assay) and 0.811 ng ml (by IDA chromagrid assay). The developed novel PoC chromagrid-lightbox system is capable of on-site detection of monocrotophos in environmental as well as food samples. This system is able to be manufacture prudently using recyclable waste plastic. Overall, such developed eco-friendly PoC testing system will surely manage rapid detection of monocrotophos pesticide needed for environmental and sustainable agricultural management.