Fluorescent hydrogel test kit coordination with smartphone: Robust performance for on-site dimethoate analysis

Publication date: Available online 18 September 2019Source: Biosensors and BioelectronicsAuthor(s): Deshuai Kong, Rui Jin, Tianshuang Wang, Hongxia Li, Xu Yan, Dandan Su, Caileng Wang, Fangmeng Liu, Peng Sun, Xiaomin Liu, Yuan Gao, Jian Ma, Xishuang Liang, Geyu LuAbstractPrecise monitoring of pesticide with portable device was challenging because it required high sensitivity, short response time, strong stability and excellent selectivity. Herein, we newly constructed a stimuli-responsive hydrogel (SRHg)-based portable kit by embedding copper nanoparticles (CuNPs) in agarose hydrogel. In this work, dimethoate as inhibitor of urease restrained the generation of ammonia, which reduced in-situ etching of CuNPs, resulting in the fluorescence color response of test kit under ultraviolet illumination. Interestingly, by means of smartphone-based nanocolorimetry, the photo image of portable kit could be translated into digital information using ImageJ software, achieving a direct quantitative tool for dimethoate identification. The simplicity of SRHg-based portable kit combined with smartphone-based color recognition not only improved the analysis sensitivity (detection limit of 1.0 μg L−1), accuracy and stability, but also simplified operation process and shortened sample-to-answer analysis time (55 min), demonstrating that the methodology met the needs of daily testing and provided a new sight for on-site monitoring of food safety and human health.
Source: Biosensors and Bioelectronics - Category: Biotechnology Source Type: research