Development of paper-based color test-strip for drug detection in aquatic environment: Application to oxytetracycline

Abstract

The wide use of antibiotics in aquaculture has led to the emergence of resistant microbial species. It should be avoided/minimized by controlling the amount of drug employed in fish farming. For this purpose, the present work proposes test-strip papers aiming at the detection/semi-quantitative determination of organic drugs by visual comparison of color changes, in a similar analytical procedure to that of pH monitoring by universal pH paper. This is done by establishing suitable chemical changes upon cellulose, attributing the paper the ability to react with the organic drug and to produce a color change. Quantitative data is also enabled by taking a picture and applying a suitable mathematical treatment to the color coordinates given by the HSL system used by windows.As proof of concept, this approach was applied to oxytetracycline (OXY), one of the antibiotics frequently used in aquaculture. A bottom-up modification of paper was established, starting by the reaction of the glucose moieties on the paper with 3-triethoxysilylpropylamine (APTES). The so-formed amine layer allowed binding to a metal ion by coordination chemistry, while the metal ion reacted after with the drug to produce a colored compound. The most suitable metals to carry out such modification were selected by bulk studies, and the several stages of the paper modification were optimized to produce an intense color change against the concentration of the drug. The paper strips were applied to the analysis of spiked environmental water, allowing a quantitative determination for OXY concentra-tions as low as 30 ng/mL. In general, this work provided a simple, method to screen and discriminate tetracycline drugs, in aquaculture, being a promising tool for local, quick and cheap monitoring of drugs.

A colorimetric biosensor using Fe3O4 nanoparticles for highly sensitive and selective detection of tetracyclines

“…These results demonstrate that the proposed method can sensitively detect TCs. As shown in Tables 1, the value of the LOD was comparable to previously reported values obtained from the electrochemical, [29] high performance liquid chromatography, [30] paper-based color test-strip [31] and electrochemiluminescence biosensors. [32] The repeatability of the proposed method is evaluated by six repeated measurements of 500nM OTC, and the relative standard deviation is 1.5%, proving the reliability of the detection method.…”

A review on advances in methods for modification of paper supports for use in point-of-care testing

“…For example, cellulose paper was modified with 3-triethoxysilylpropylamine (APTES) and the prepared paper-based test strip was used to detect oxitetracycline (OXY) through observing color change (Fig. 10a) [132]. The modification method can aminate the paper surface using APTES based on the self-assembly approach, because the amine group can bind metal ions (Fe(III) and Cu(II)) to form color.…”

A cellulose-based colour test-strip for equipment-free drug detection on-site: application to sulfadiazine in aquatic environment

“…These works involved a colourimetric reaction between a target antibiotic and a suitable reagent, entrapped within a plasticized PVC support. Another test-strip for antibiotic involves a cellulose paper substrate that was further modified in a self-assembled monolayer process [43]. The use of a cellulose support offers the advantage of leading to a detection system that is inexpensive and environmentally safe, while delivering waste materials that are not critical for the environment.…”

“…In general, Cu(II) establishes stable complexes with amine derived compounds, and this could be a simple way to bind it to a cellulose substrate [43]. However, this could be also a disturbing element if Cu(II) would bind to the amine groups with high affinity, thereby decreasing the amount of available copper for a subsequent reaction with SDZ.…”