Microfluidic electrophoretic non-enzymatic kanamycin assay making use of a stirring bar functionalized with gold-labeled aptamer, of a fluorescent DNA probe, and of signal amplification via hybridization chain reaction

摘要: The authors describe an enzyme-free aptamer-based assay for the determination of model antibiotic kanamycin (Kana). method is making use (a) microfluidic chip electrophoresis; (b) a stirring bar carrying gold-labeled aptamer probe, and (c) hybridization chain reaction (HCR) signal amplification. Firstly, (length: 1 cm; diameter: 0.2 mm) was modified with large amount duplex DNA then hybridized its partially complementary chains (cDNA). In presence Kana, binding between Kana unwinds structures releases corresponding cDNA into supernatant. released triggers HCR in H1 H2 hairpin to produce different lengths. At same time, amounts are reduced. decreased H1/H2 after several cycles can be used quantify kana 1 pg·mL-1 10 ng·mL-1, detection limit 0.29 pg·mL-1. generated by reading fluorescence, best at excitation/emission maxima 470/525 nm. whole process takes 3 min only. employed spiked milk fish samples. Results consistent those enzyme linked immunosorbent assay. has high throughput, selectivity, amplification capability. Graphical abstract Schematic functionalized acting as capture probe. It target release primer simultaneously. inducing consumption H2. After certain mixture injected MCE platform electrophoretic separation fluorometric detection.