Ultrasensitive ratiometric detection of Pb2+ using DNA tetrahedron-mediated hyperbranched hybridization chain reaction

• Published in: Analytica chimica acta Vol. 1147; pp. 170 - 177
• Main Authors: Ji, Pingping, Han, Guimei, Huang, Yan, Jiang, Hongxin, Zhou, Qiwen, Liu, Xiaowei, Kong, Deming
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 22.02.2021
• Subjects: Biosensing; DNAzyme; Fluorescence resonance energy transfer (FRET); Pb2+ detection; Ratiometric detection; Tetrahedral DNA nanostructure (TDN); DNAzyme; Pb2+ detection; Ratiometric detection; Fluorescence resonance energy transfer (FRET); Biosensing; Tetrahedral DNA nanostructure (TDN)
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2020.12.050

A fluorescent sensing strategy was developed for rapid, highly sensitive and specific detection of lead (II) ion (Pb2+) on the basis of Pb2+ DNAzyme-controlled tetrahedral DNA nanostructure (TDN)-mediated hyper-branched hybridization chain reaction (hHCR). In this strategy, DNA hairpins used for HCR amplification are modified on the four vertexes of TDN, which are then used to perform rapid TDN-hHCR in the presence of an initiator strand, producing large-sized cross-linked reaction products and thus giving greatly improved fluorescence resonance energy transfer (FRET) signal output. Pb2+ DNAzyme catalyzes the cleavage of the initiator strand, inhibiting the initiation of TDN-hHCR and giving decreased FRET signal. Synergetic signal amplification of Pb2+ DNAzyme-catalyzed cleavage reaction and subsequent TDN-hHCR confers the sensing platform with ultrahigh sensitivity. As low as 0.25 pM Pb2+ can be detected by using either signal “turn-on” or “turn-off” mode. The whole detection process can be finished within 20 min. Strong anti-interference capacity of FRET-based ratiometric detection and high specificity of Pb2+ DNAzyme endow the sensing platform with great practical application potential, which was demonstrated by the accurate detection of Pb2+ in real river water, fruit, vegetable and grain samples. A fluorescent sensing strategy was developed for rapid, highly sensitive and specific detection of lead (II) ion (Pb2+) on the basis of Pb2+ DNAzyme-controlled tetrahedral DNA nanostructure (TDN)-mediated hyper-branched hybridization chain reaction (hHCR). In this strategy, DNA hairpins used for HCR amplification are modified on the four vertexes of TDN, which are then used to perform rapid TDN-hHCR in the presence of an initiator strand, producing large-sized cross-linked reaction products and thus giving greatly improved fluorescence resonance energy transfer (FRET) signal output. Pb2+ DNAzyme catalyzes the cleavage of the initiator strand, inhibiting the initiation of TDN-hHCR and giving decreased FRET signal. Synergetic signal amplification of Pb2+ DNAzyme-catalyzed cleavage reaction and subsequent TDN-hHCR confers the sensing platform with ultrahigh sensitivity. As low as 0.25 pM Pb2+ can be detected by using either signal “turn-on” or “turn-off” mode. The whole detection process can be finished within 20 min. Strong anti-interference capability of FRET-based ratiometric detection and high specificity of Pb2+ DNAzyme endow the sensing platform with great practical application potential, which was demonstrated by the accurate detection of Pb2+ in real river water, fruit, vegetable and grain samples. [Display omitted] •A new fluorescent Pb2+-sensing platform is developed using DNA tetrahedron-mediated hyperbranched HCR.•The sensing platform shows an ultrahigh sensitivity with a detection limit as low as 0.25 pM.•Ratiometric detection of Pb2+ can be achieved by signal “turn-on” or “turn-off” mode.•Rapid Pb2+ detection can be achieved within 20 min.•The sensing platform works well for the accurate detection of Pb2+ in real river water, fruit, vegetable and grain samples.