An Image Analysis-Assisted Paper-Based Colorimetric Aptasensor for Simple and Rapid Malathion Detection

Paper-based colorimetric sensors have been widely applied as cost-effective tools for on-site pesticide detection. The availability of inexpensive imaging technologies, such as smartphones, has enhanced the efficiency of detection methodologies. This work describes the development of an image analysis-assisted paper-based colorimetric aptasensor for malathion (MLT) detection. The sensing paper was fabricated by immobilizing a mixture of citrate-capped gold nanoparticles (cit-AuNPs) and thiolated DNA aptamer (Apt) onto Whatman filter paper. After a ۳-minute reaction, the paper exhibited a visible color change in the presence of MLT due to cit-AuNP aggregation. Smartphone images of the sensing paper, captured before and after MLT addition, were processed using ImageJ software to obtain red, green, and blue (RGB) values, with the response expressed as ΔRGB. The aptasensor achieved a limit of detection (LOD) of ۰.۶۷ μM with a linear range of ۱۰۰–۱,۰۰۰ μM. This paper-based colorimetric aptasensor provides a simple and rapid method for on-site MLT detection.

کلیدواژه ها:

Aptasensor ، image analysis ، Paper-based colorimetric ، Gold Nanoparticles ، Malathion