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Fluorescent aptasensors for sensitive detection of lead ions based on structure-switching DNA beacon probe and exonuclease I-mediated signal amplification.
Su, Ruifang; Li, Zhihong; Yang, Chuanyu; Li, Ying; Wang, Junyang; Sun, Chunyan.
Afiliação
  • Su R; Department of Food Quality and Safety, College of Food Science and Engineering, Jilin University, Changchun 130062, China.
  • Li Z; Department of Food Quality and Safety, College of Food Science and Engineering, Jilin University, Changchun 130062, China.
  • Yang C; Department of Food Quality and Safety, College of Food Science and Engineering, Jilin University, Changchun 130062, China.
  • Li Y; Department of Food Quality and Safety, College of Food Science and Engineering, Jilin University, Changchun 130062, China.
  • Wang J; Department of Food Quality and Safety, College of Food Science and Engineering, Jilin University, Changchun 130062, China. Electronic address: junyangw@jlu.edu.cn.
  • Sun C; Department of Food Quality and Safety, College of Food Science and Engineering, Jilin University, Changchun 130062, China; Chongqing Research Institute, Jilin University, Chongqing 401123, China. Electronic address: sunchuny@jlu.edu.cn.
Spectrochim Acta A Mol Biomol Spectrosc ; 320: 124643, 2024 Nov 05.
Article em En | MEDLINE | ID: mdl-38901233
ABSTRACT
Herein, two simple fluorescent signal-on sensing strategies for detecting lead ions (Pb2+) were established based on structure-switching aptamer probes and exonuclease-assisted signal amplification strategies. Two hairpin-structure fluorescent probes with blunt-ended stem arms were designed by extending the base sequence of Pb2+ aptamer (PS2.M) and labelling the probes with FAM (in probe 1) and 2-aminopurine (2-AP) (in probe 2), respectively. In method 1, graphene oxide (GO) was added to adsorb probe 1 and quench the fluorescence emission of FAM to achieve low fluorescent background. In method 2, fluorescent 2-AP molecule inserted into the double-stranded DNA of probe 2 was quenched as a result of base stacking interactions, leading to a simplified, quencher-free approach. The addition of Pb2+ can induce the probes to transform into G-quadruplex structures, exposing single DNA strands at the 3' end (the extended sequences). This exposure enables the activation of exonuclease I (Exo I) on the probes, leading to the cleavage effect and subsequent release of free bases and fluorophores, thereby resulting in amplified fluorescence signals. The two proposed methods exhibit good specificity and sensitivity, with detection limits of 0.327 nM and 0.049 nM Pb2+ for method 1 and method 2, respectively, and have been successfully applied to detect Pb2+ in river water and fish samples. Both detection methods employ the structure-switching aptamer probes and can be completed in two or three steps without the need for complex analytical instruments. Therefore, they have a broad prospect in the sensitive and simple detection of lead ion contamination in food and environmental samples.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Espectrometria de Fluorescência / Técnicas Biossensoriais / Aptâmeros de Nucleotídeos / Exodesoxirribonucleases / Limite de Detecção / Corantes Fluorescentes / Chumbo Limite: Animals Idioma: En Revista: Spectrochim Acta A Mol Biomol Spectrosc Ano de publicação: 2024 Tipo de documento: Article

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Espectrometria de Fluorescência / Técnicas Biossensoriais / Aptâmeros de Nucleotídeos / Exodesoxirribonucleases / Limite de Detecção / Corantes Fluorescentes / Chumbo Limite: Animals Idioma: En Revista: Spectrochim Acta A Mol Biomol Spectrosc Ano de publicação: 2024 Tipo de documento: Article