Paper chip-based colorimetric sensing assay for ultra-sensitive detection of residual kanamycin

[Display omitted] •We developed paper chip-based colorimetric sensing assay for Kanamycin detection.•The 14nm of sodium citrate capped gold nanoparticle was used for colorimetric indicator.•For point-of-care monitoring of Kanamycin, paper chip was prepared by wax printing.•Kanamycin was detected as low as 3.35nM (1.95ppb) by naked eye on the paper chip.•This simple strategy exhibited high accuracy for detecting Kanamycin in milk samples. Kanamycin, an aminoglycoside antibiotic, is extensively used to treat bacterial infections by interrupting protein synthesis. Overuse of kanamycin can lead to undesirable outcomes such as antibiotic resistance in humans. Thus, a precise detection strategy for monitoring kanamycin in animal-derived foods is strongly required. In this study, a novel paper chip-based label-free, simple sensing assay was developed. Gold nanoparticles for colorimetric assays were synthesized and characterized, and the paper chip pattern was printed using a wax printer. Through the colorimetric sensing assay on the paper chip, kanamycin was detected at levels as low as 3.35nM (1.95ppb) by the naked eye and using RGB color analysis techniques. In addition, this technique was also used for detection of kanamycin in milk samples. Compared to other detection systems, the use of the presented colorimetric detection system renders further analysis unnecessary. To our knowledge, this is the first report of colorimetric detection of kanamycin using the paper chip system. This simple, equipment-free, rapid, and ultra-sensitive paper chip-based kanamycin detection system provides superior field applicability for the monitoring of food and environmental safety.