451. Mimicking an Enzyme-Based Colorimetric Aptasensor for Antibiotic Residue Detection in Milk Combining Magnetic Loop-DNA Probes and CHA-Assisted Target Recycling Amplification.
- Author
-
Luan Q, Gan N, Cao Y, and Li T
- Subjects
- Animals, Aptamers, Nucleotide chemistry, Benzidines chemistry, Biosensing Techniques instrumentation, Cattle, Colorimetry, DNA chemistry, Food Contamination analysis, Gold chemistry, Kanamycin analysis, Limit of Detection, Anti-Bacterial Agents analysis, Biosensing Techniques methods, Drug Residues analysis, Milk chemistry
- Abstract
A mimicking-enzyme-based colorimetric aptasensor was developed for the detection of kanamycin (KANA) in milk using magnetic loop-DNA-NMOF-Pt (m-L-DNA) probes and catalytic hairpin assembly (CHA)-assisted target recycling for signal amplification. The m-L-DNA probes were constructed via hybridization of hairpin DNA H1 (containing aptamer sequence) immobilized magnetic beads (m-H1) and signal DNA (sDNA, partial hybridization with H1) labeled nano Fe-MIL-88NH
2 -Pt (NMOF-Pt-sDNA). In the presence of KANA and complementary hairpin DNA H2, the m-L-DNA probes decomposed and formed an m-H1/KANA intermediate, which triggered the CHA reaction to form a stable duplex strand (m-H1-H2) while releasing KANA again for recycling. Consequently, numerous NMOF-Pt-sDNA as mimicking enzymes can synergistically catalyze 3,3',5,5'-tetramethylbenzidine (TMB) for color development. The aptasensor exhibited high selectivity and sensitivity for KANA in milk with a detection limit of 0.2 pg mL-1 within 30 min. The assay can be conveniently extended for on-site screening of other antibiotics in foods by simply changing the base sequence of the probes.- Published
- 2017
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