Ultra-sensitive detection of kanamycin for food safety using a reduced graphene oxide-based fluorescent aptasensor

Abstract

Overuse of antibiotics has caused serious problems, such as appearance of super bacteria, whose accumulation in the human body through the food chain is a concern. Kanamycin is a common antibiotic used to treat diverse infections; however, residual kanamycin can cause many side effects in humans. Thus, development of an ultra-sensitive, precise, and simple detection system for residual kanamycin in food products is urgently needed for food safety. In this study, we identified kanamycin-binding aptamers via a new screening method, and truncated variants were analyzed for optimization of the minimal sequence required for target binding. We found various aptamers with high binding affinity from 34.7 to 669 nanomolar Kdapp values with good specificity against kanamycin. Furthermore, we developed a reduced graphene oxide (RGO)-based fluorescent aptasensor for kanamycin detection. In this system, kanamycin was detected at a concentration as low as 1 pM (582.6 fg/mL). In addition, this method could detect kanamycin accurately in kanamycin-spiked blood serum and milk samples. Consequently, this simple, rapid, and sensitive kanamycin detection system with newly structural and functional analysis aptamer exhibits outstanding detection compared to previous methods and provides a new possibility for point of care testing and food safety.

Recent Advances in Optical Detection of Aminoglycosides

“…Compared with turn-off FL sensing methods, turn-on FL strategies showed a lower background and higher detection sensitivity. The graphene-based FRET aptasensor exhibited the highest sensitivity for the detection of kanamycin (1 pM) [44]. The high sensitivity may be attributed to the efficient quench ability of graphene, which leads to a low background, and a good binding ability of kanamycin to the aptamer.…”

Aptamer-Based Biosensors for Antibiotic Detection: A Review

“…Fluorescence, as one of the most common optical techniques, has been used in the fabrication of aptasensors for kanamycin detection [ 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 ]. Generally, the binding affinity of an aptamer towards its target decreases by tagging the aptamer with a fluorescent dye [ 83 ].…”

The Growing Interest in Development of Innovative Optical Aptasensors for the Detection of Antimicrobial Residues in Food Products

“…One major advantage of aptamers is that they are easily modifiable via the addition of functional groups. Aptamers could be immobilized onto a surface through functional groups that can be added during their chemical synthesis (e.g., biotinylated CAP aptamer-functionalized magnetic nanoparticles (MNPs) [40], thiol modified aptamer conjugated on gold nanoparticles (AuNPs) [41]), as well as reporter molecules (e.g., fluorescein, biotin) can be combined with aptamers (e.g., carboxyfluorescein (FAM)-labeled aptamer [42], cyanine 3-labeled aptamer [43], horseradish peroxidase (HRP)-labeled aptamer by biotin-streptavidin system [44]). Aptamers can be labeled without loss of affinity.…”