title: Ultrasensitive fluorescence polarization aptasensors based on exonuclease signal amplification and polystyrene nanoparticle amplification.
abstract: Here, we combine T7 exonuclease (T7 Exo) signal amplification and polystyrene nanoparticle (PS NP) amplification to develop novel fluorescence polarization (FP) aptasensors. The binding of a target/open aptamer hairpin complex or a target/single-stranded aptamer complex to dye-labeled DNA bound to PS NPs, or the self-assembly of two aptamer subunits (one of them labeled with a dye) into a target/aptamer complex on PS NPs leads to the cyclic T7 Exo-catalyzed digestion of the dye-labeled DNA or the dye-labeled aptamer subunit. This results in a substantial decrease in the FP value for the amplified sensing process. Our newly developed aptasensors exhibit a sensitivity five orders of magnitude higher than that of traditional homogeneous aptasensors and a high specificity for the target molecules. These distinct advantages of our proposed assay protocol make it a generic platform for the design of amplified aptasensors for ultrasensitive detection of various target molecules.
authors.affiliation: Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), College of Chemistry and Pharmacy, Guangxi Normal University, Guilin 541004 (China). zhaoshulin001@163.com.
authors.forename: Yong
authors.initials: Y
authors.lastname: Huang
authors.forename: Xiaoqian
authors.initials: X
authors.lastname: Liu
authors.forename: Ming
authors.initials: M
authors.lastname: Shi
authors.forename: Shulin
authors.initials: S
authors.lastname: Zhao
authors.forename: Kun
authors.initials: K
authors.lastname: Hu
authors.forename: Zhen-Feng
authors.initials: ZF
authors.lastname: Chen
authors.forename: Hong
authors.initials: H
authors.lastname: Liang
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015342:DNA Probes; D005090:Exodeoxyribonucleases / Q000737:chemistry*; D005454:Fluorescence Polarization / Q000295:instrumentation*; D057230:Limit of Detection; D053758:Nanoparticles; D011137:Polystyrenes / Q000737:chemistry*
chemical_list: D052157:Aptamers, Nucleotide; D015342:DNA Probes; D011137:Polystyrenes; D005090:Exodeoxyribonucleases; C046264:gene b exonuclease
keywords: amplification; aptasensors; exonuclease; nanoparticles; polarization