Colorimetric method for determination of bisphenol A based on aptamer-mediated aggregation of positively charged gold nanoparticles
| Autor: | Chunyan Sun, Ying Li, Jiaxin Bie, Fei Shen, Wei Jiang, Yeli Luo, Jingyue Xu, Jiajia Guo |
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| Rok vydání: | 2015 |
| Předmět: | |
| Zdroj: | Microchimica Acta. 182:2131-2138 |
| ISSN: | 1436-5073 0026-3672 |
| DOI: | 10.1007/s00604-015-1547-z |
| Popis: | A sensitive, specific and rapid colorimetric aptasensor for the determination of the plasticizer bisphenol A (BPA) was developed. It is based on the use of gold nanoparticles (AuNPs) that are positively charged due to the modification with cysteamine which is cationic at near-neutral pH values. If aptamers are added to such AuNPs, aggregation occurs due to electrostatic interactions between the negatively-charged aptamers and the positively-charged AuNPs. This results in a color change of the AuNPs from red to blue. If a sample containing BPA is added to the anti-BPA aptamers, the anti-BPA aptamers undergo folding via an induced-fit binding mechanism. This is accompanied by a conformational change, which prevents the aptamer-induced aggregation and color change of AuNPs. The effect was exploited to design a colorimetric assay for BPA. Under optimum conditions, the absorbance ratio of A 527/A 680 is linearly proportional to the BPA concentration in the range from 35 to 140 ng∙mL−1, with a detection limit of 0.11 ng∙mL−1. The method has been successfully applied to the determination of BPA in spiked tap water and gave recoveries between 91 and 106 %. Data were in full accordance with results obtained from HPLC. This assay is selective, easily performed, and in our perception represents a promising alternative to existing methods for rapid quantification of BPA. |
| Databáze: | OpenAIRE |
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