Determination of norfloxacin residues in foods by exploiting the coffee‐ring effect and paper‐based microfluidics device coupling with smartphone‐based detection

Abstract

By utilizing the coffee‐ring effect and microfluidic paper‐based analytical devices (µPADs), this study improved the sensitivity of the determination of norfloxacin in four different food matrices. Micro‐PADs in this study were fabricated by designing and embedding wax channels onto cellulose‐based filter paper through printing and subjecting the paper to heat to allow the wax to penetrate the paper. Determination of norfloxacin concentration in food samples was achieved by monitoring the colorimetric reaction that occurred between norfloxacin and the added iron (III) nitrate nonahydrate in 5 mM ammonia in each reaction chamber. A transition metal hydroxide was formed through this reaction that resulted in the formation of a solid precipitate to enable the antibiotic to bind to the iron molecule via coordination chemistry. This metal ion–antibiotic complex generated a visible color change. Following the colorimetric reaction, images were taken and subsequently analyzed via ImageJ to determine the relative pixel intensity that was used to infer norfloxacin concentration. The analytical sensitivity of this device was determined to be as low as 50 ppm when analyzing the inner‐ring reaction, and as low as 5 ppm when analyzing the outer coffee ring thereby allowing for an alternative cheaper, faster, and more user‐friendly method to detect norfloxacin than the conventional methods. Practical Application This novel paper‐based microfluidic device can achieve the detection of antibiotic residues in agrifoods in a faster, cheaper, and more user‐friendly manner.

Development and Evaluation of a Paper-Based Microfluidic Device for Detection of Listeria monocytogenes on Food Contact and Non-Food Contact Surfaces

“…Demonstration of µPAD platforms for detection of pathogens in the food industry is limited. Examples include [ 11 , 28 , 29 , 30 ], among others. This publication addresses gaps in the literature: the application of µPADs to a food processing environment and comparison to standard methods.…”

“…When µPAD diagnostics are employed with enzymatic detection, a catalytic colorimetric response is observed. Enzymatic detection paired with µPADs has been used to detect foodborne pathogens [ 29 ], to discriminate between pathogenic and nonpathogenic species [ 11 ], and to detect the presence of antibiotics [ 28 ].…”

Microfluidic Paper-Based Analytical Devices for the Determination of Food Contaminants: Developments and Applications

“…Copyright 2020, with permission from Elsevier. (C) Schematic illustration of the fabrication and testing process of the μPAD for antibiotic colorimetric detection . Copyright 2020, with permission from John Wiley and Sons.…”

Recent Advances in Microfluidic Paper-Based Analytical Devices toward High-Throughput Screening

“…The intensity of a color signal can be interpreted using imaging software, where a pixel value is related to the concentration of the analyte. The data can be analyzed by using such a system [ 129 , 130 , 131 , 132 ].…”