An aptamer-based colorimetric assay for chloramphenicol using a polymeric HRP-antibody conjugate for signal amplification

作者：Gao Huiju; Pan Daodong^*; Gan Ning; Cao Jinxuan; Sun Yangying; Wu Zhen; Zeng Xiaoqun

来源：Microchimica Acta, 2015, 182(15-16): 2551-2559.

DOI：10.1007/s00604-015-1632-3

• Colorimetric assay
• PowerVision
• DNA antibody
• Chloramphenicol
• Magnetic nanoparticles
• Gold nanoparticles

We describe an aptamer-based colorimetric assay for chloramphenicol (CAP) based on the ability of anti-single-stranded DNA antibody (anti-ssDNA Ab) to recognize ssDNA, and the catalytic ability of PowerVision (PV), which is a polymeric conjugate of horseradish peroxidase and antibody with a high enzyme-to-antibody ratio. The complementary DNA of the aptamer (cDNA) was immobilized on magnetic gold nanoparticles (Fe3O4@Au) and used as a capture probe (AuMNPs-cDNA). The ssDNA Ab and PV were conjugated to AuNPs to form signal tags that recognize ssDNA with anti-ssDNA Ab to form beads containing the amplified probe (AuMNPs-cDNA@anti-ssDNA Ab/PV-AuNPs). The PV on their surface catalyzes the oxidation of the substrate 3,3',5,5'-tetramethylbenzidine to produce a color change which is quantified by absorptiometry at 652 nm. The assay has a linear calibration plot for CAP in the 0.01 to 100 ng mL(-1) range, with a detection limit as low as 3 pg mL(-1). The method was successfully employed to detect CAP in real samples. Results were consistent with data obtained using a conventional enzyme-linked immunosorbent assay.

• 出版日期2015-11
• 单位宁波大学