LAUSR

On-site quantitative analysis pesticide is of significant importance for addressing serious public health issues in clinical, food and environmental settings. Herein, we designed a novel smartphone-assisted sensing platform for on-site monitoring of 2, 4-dichlorophenoxyacetic acid (2, 4-D) based on carbon dots/cobalt oxyhydroxide nanosheets (CDs/CoOOH) composite. In this work, red emissive CDs/CoOOH composite was proposed as signal indicator for shielding background interference, enhancing anti-interference capability. 2, 4-D as inhibitor of alkaline phosphatase could specifically suppress the produce of ascorbic acid, which restrained in-situ etching of CDs/CoOOH composite and further triggered the fluorescence response of biosensor. By employing lab-on-smartphone based device and self-designed application software, the fluorescence image was directly captured and analyzed with a sensitive detection limit of 100 μg L-1 for 2, 4-D. Merging the CDs/CoOOH composite-based fluorometric system with the smartphone-assisted optical reader, such a cost-effective and portable platform provided a new sight for on-site monitoring pesticide and expanded application prospect in the field of biological analysis.