title: A cascade signal amplification strategy for surface enhanced Raman spectroscopy detection of thrombin based on DNAzyme assistant DNA recycling and rolling circle amplification.
abstract: A sensitive protocol for surface enhanced Raman spectroscopy (SERS) detection of thrombin is designed with R6G-Ag NPs as a signal tag by combining DNAzyme assistant DNA recycling and rolling circle amplification (RCA). Molecular beacon (MB) as recognition probe immobilizes on the glass slides and performs the amplification procedure. After thrombin-induced structure-switching DNA hairpins of probe 1, the DNAzyme is liberated from the caged structure, which hybridizes with the MB for cleavage of the MB in the presence of cofactor Zn(2+) and initiates the DNA recycling process, leading to the cleavage of a large number of MB and the generation of numerous primers for triggering RCA reaction. The long amplified RCA product which contained hundreds of tandem-repeat sequences, which can bind with oligonucleotide functionalized Ag NPs reporters. The attached signal tags can be easily read out by SERS. Because of the cascade signal amplification, these newly designed protocols provides a sensitive SERS detection of thrombin down to the femolar level (2.3fM) with a linear range of 5 orders of magnitude (from 10(-14) to 10(-9)M) and have high selectivity toward its target protein. The proposed method is expected to be a good clinical tool for the diagnosis of a thrombotic disease.
authors.affiliation: Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical College, 221004 Xuzhou, China. Electronic address: jsxzgfl@sina.com.
authors.forename: Fenglei
authors.initials: F
authors.lastname: Gao
authors.affiliation: Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical College, 221004 Xuzhou, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Du
authors.affiliation: Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical College, 221004 Xuzhou, China.
authors.forename: Daoquan
authors.initials: D
authors.lastname: Tang
authors.affiliation: Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical College, 221004 Xuzhou, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical College, 221004 Xuzhou, China.
authors.forename: Yanzhuo
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical College, 221004 Xuzhou, China.
authors.forename: Lixian
authors.initials: L
authors.lastname: Zhang
mesh_terms: D001483:Base Sequence; D015374:Biosensing Techniques / Q000379:methods*; D015342:DNA Probes / Q000235:genetics; D021881:DNA, Catalytic / Q000378:metabolism*; D006801:Humans; D053768:Metal Nanoparticles; D008969:Molecular Sequence Data; D021141:Nucleic Acid Amplification Techniques; D012834:Silver; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013917:Thrombin / Q000032:analysis*
chemical_list: D015342:DNA Probes; D021881:DNA, Catalytic; D012834:Silver; D013917:Thrombin
keywords: DNAzyme; Rolling circle amplification; Signal amplification; Surface enhanced Raman spectroscopy