Polymer‐Templated Perylene‐Probe Noncovalent Self‐Assembly: A New Strategy for Label‐Free Ultrasensitive Fluorescence Turn‐On Biosensing |
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Authors: | Yan Wang Jian Chen Dr Huping Jiao Yang Chen Wenying Li Qingfeng Zhang Prof?Dr Cong Yu |
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Institution: | 1. State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (P.R. China);2. Graduate School of the Chinese Academy of Sciences, Beijing 100039 (P.R. China) |
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Abstract: | A new label‐free fluorescence turn‐on strategy for highly sensitive biosensing has been developed. A negatively charged perylene probe was synthesized. Polycations could induce aggregation of the perylene probe through noncovalent interactions and the fluorescence of the probe’s monomer was efficiently quenched. Upon addition of a single‐stranded nucleic acid, competitive binding of the negatively charged nucleic acid (a polyanion) to the cationic polymer resulted in the release of a monomer and thus a turn‐on fluorescence signal was detected. Without the use of any amplification techniques, a detection limit of 2 pM DNA was obtained. Based on these results, an assay strategy for the highly sensitive detection of alkaline phosphatase (ALP) activity has been demonstrated. λ Exonuclease (λ exo) could degrade 5′‐phosphorylated single‐stranded DNA. However, when the DNA sample was treated with ALP, the phosphate functional group was removed by ALP and it could no longer be degraded by λ exo. Binding of the DNA to the perylene probe–polycation complex resulted in a turn‐on fluorescence signal, which could be used for sensing of ALP. The method is highly sensitive, a limit of detection as low as 0.02 mU mL?1 ALP was obtained. Our method is simple, convenient, highly sensitive, and inexpensive. |
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Keywords: | biosensors enzyme activity fluorescence nucleic acid self‐assembly |
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