Development of a Screening Method for Sulfamethoxazole in Environmental Water by Digital Colorimetry Using a Mobile Device

Abstract

Antibiotic resistance is a major health concern of the 21st century. The misuse of antibiotics over the years has led to their increasing presence in the environment, particularly in water resources, which can exacerbate the transmission of resistance genes and facilitate the emergence of resistant microorganisms. The objective of the present work is to develop a chemosensor for screening of sulfonamides in environmental waters, targeting sulfamethoxazole as the model analyte. The methodology was based on the retention of sulfamethoxazole in disks containing polystyrene divinylbenzene sulfonated sorbent particles and reaction with p-dimethylaminocinnamaldehyde, followed by colorimetric detection using a computer-vision algorithm. Several color spaces (RGB, HSV and CIELAB) were evaluated, with the coordinate a_star, from the CIELAB color space, providing the highest sensitivity. Moreover, in order to avoid possible errors due to variations in illumination, a color palette is included in the picture of the analytical disk, and a correction using the a_star value from one of the color patches is proposed. The methodology presented recoveries of 82–101% at 0.1 µg and 0.5 µg of sulfamethoxazole (25 mL), providing a detection limit of 0.08 µg and a quantification limit of 0.26 µg. As a proof of concept, application to in-field analysis was successfully implemented.

Development of a synthesis strategy for sulfamethoxazole derivatives and their coupling with hydrogel microparticles

“…This raises the need for the development of new, fast, and cost-effective technologies enabling point-of-use analysis to monitor and quantify the distribution of SMX and other antibiotics. Over the last years, various new approaches for sulfonamide detection were published, covering different methods such as immunochemical detection 14 , colorimetric approaches 15 as well as electrochemical technologies 16,17 . Other emerging technologies are based on biosensing nano-and microparticles as probes for detection with a broad application field [18][19][20][21][22] .…”