An aptamer-based colorimetric Pt(II) assay based on the use of gold nanoparticles and a cationic polymer

作者：Sang, Fuming^*; Liu, Jia; Zhang, Xue; Pan, Jianxin

来源：Microchimica Acta, 2018, 185(5): 267.

DOI：10.1007/s00604-018-2794-6

• Colorimetric
• Aptasensor
• Platinum ions
• Cationic polymer
• AuNPs aggregation

A colorimetric method is described for the determination of Pt(II). It is based on the use of gold nanoparticles (AuNPs) which are known to aggregate in the presence of a cationic polymer such as poly(diallyldimethylammonium chloride) (PDDA). If, however, a mismatched aptamer (AA) electrostatically binds to PDDA, aggregation is prevented. Upon the addition of Pt(II), it will bind to the aptamer and induce the formation of a hairpin structure. Hence, interaction between aptamer and PDDA is suppressed and PDDA will induce the aggregation of the AuNPs. This is accompanied by a color change from red to blue. The effect can be observed with bare eyes and quantified by colorimetry via measurement of the ratio of absorbances at 610 nm and 520 nm. Response is linear in the 0.24-2 mu M Pt(II) concentration range, and the detection limit is 58 nM. The assay is completed within 15 min and selective for Pt(II) even in the presence of other metal ions. It was successfully applied to the rapid determination of Pt(II) in spiked soil samples.

• 出版日期2018-5
• 单位哈尔滨工业大学