Eco-friendly screening method for sulfonamides using a 3D handheld smartphone-based fluorescence detection device and graphene nanoplatelet-packed pipette tip microextraction

Abstract

<p>A sensitive, miniaturized, and low-cost method combining pipette tip solid-phase microextraction and</p><p>smartphone-based fluorescent detection has been developed for the determination of total sulfonamides in water</p><p>samples. Sulfonamides antibiotics (SAs) are contaminants commonly found in water matrices, leading to</p><p>antibiotic-resistant bacteria and risks to human health and the environment. Thus, its real-time monitoring is</p><p>essential to the risk assessment, and the subsequent management of any water supply. Sample preparation</p><p>consisted of extraction/preconcentration of SAs using graphene nanoplatelets packed inside a pipette tip, followed</p><p>by fluorescent derivatization using fluorescamine inside the microplate reader, both 3D printed. Subsequently,</p><p>a 3D printed detection platform that houses monochromatic LED strips as radiation source and a</p><p>smartphone as detector have been used for determination total SAs. Digital image processing was based on the</p><p>RGB colour model using image J software with its Readplate plugin and the green intensity channel was used as</p><p>analytical signal due to its higher sensitivity. Several factors that affect the extraction efficiency and detection</p><p>have been optimized. Under the optimized conditions, good linearity for SAs studied were obtained in a range of</p><p>10–60 μg L 1 with r ≥ 0.990 and limits of detection between 2.5–3.1 μg L 1 for a sample volume of 10 mL. The</p><p>recoveries of sulfamethoxazole (as a model compound to express total SAs) spiked in diverse water matrices were</p><p>tested at two different levels showed good recoveries from 94% to 102% with RSD ≤ 7.6%. The results obtained</p><p>with the proposed method were satisfactorily compared with those obtained with a conventional spectrofluorometer</p><p>(P ≥ 0.13). This easy-to-operate system features a simple extraction procedure (up to 20-fold enrichment),</p><p>excellent sensitivity and precision, which is very useful and practical for on-site analysis. Furthermore,</p><p>three greenness evaluation methodologies (GAPI, AGREE, and AGREEprep) were used to assess the environmental</p><p>friendliness of the proposed method, demonstrating its superior performance compared to previously</p><p>published HPLC and spectrophotometric methods.</p>