Title
Colorimetric determination of ofloxacin using unmodified aptamers and the aggregation of gold nanoparticles
Author
Xiaotong Zhou, Lumei Wang, Guoqing Shen, Dongwei Zhang, Jialun Xie, Abdureyim Mamut, Weiwen Huang, Shanshan Zhou
Year
2018
Journal
Microchimica Acta
Abstract
A colorimetric method is presented for the determination of the antibiotic ofloxacin (OFL) in aqueous solution. It is based on the use of an aptamer and gold nanoparticles (AuNPs). In the absence of OFL, the AuNPs are wrapped by the aptamer and maintain dispersed even at the high NaCl concentrations. The solution with colloidally dispersed AuNPs remains red and has an absorption peak at 520 nm. In the presence of OFL, it will bind to the aptamer which is then released from the AuNPs. Hence, AuNPs will aggregate in the salt solution, and color gradually turns to blue, with a new absorption peak at 650 nm. This convenient and specific colorimetric assay for OFL has a linear response in the 20 to 400 nM OFL concentration range and a 3.4 nM detection limit. The method has a large application potential for OFL detection in environmental and biological samples.
Instrument
J-815
Keywords
Circular dichroism, DNA structure, Chemical stability, Biochemistry