title: Nanosilver-based surface-enhanced Raman spectroscopic determination of DNA methyltransferase activity through real-time hybridization chain reaction.
abstract: In this manuscript, a nanosilver enhanced SERS strategy was successfully constructed for the determination of DNA methyltransferase activity in soulution combined with hybridization chain reaction (HCR). The proposed method was mainly on the basis of excellent separation ability of magnetic microparticles (MMPs), HCR as signal amplification unit and assembled AgNPs as enhancement substrate. In the presence of M. SssI MTase, the duplex sequence (5'-CCGG-3') tethered to MMPs was methylated, which cannot be cleaved by HpaII endonuclease. The resulted DNA skeleton captured on MMPs then triggered the HCR reaction, generated a polymerized and extended symmetrical sequence, in which more biotin terminal was available for the conjugation of AgNPs-SA, leading to significantly amplified SERS response. When it was used to analyze M. SssI activity, a linear equation ∆ISERS=1215.32+446.80 cM.SssI was obtained with the M. SssI activity ranged from 0.1 to 10.0 U with the correlation coefficient (r(2)) of 0.97. The most important advantage of this method is the combination of SERS and HCR in solution for the first time and its good selectivity, which enabled the detection of even one-base mismatched sequence. The new assay method holds great promising application to be a versatile platform for sensitive, high-throughput detection, and the screening of new anticancer drugs on DNA MTase.
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China; Innovative Drug Research Centre, Chongqing University, Chongqing 401331, China.
authors.forename: Ping Ping
authors.initials: PP
authors.lastname: Hu
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.affiliation: College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
authors.forename: Shu Jun
authors.initials: SJ
authors.lastname: Zhen
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China.
authors.forename: Chun Mei
authors.initials: CM
authors.lastname: Li
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China. Electronic address: chengzhi@swu.edu.cn.
authors.forename: Cheng Zhi
authors.initials: CZ
authors.lastname: Huang
mesh_terms: D015374:Biosensing Techniques / Q000379:methods / Q000706:statistics & numerical data; D015254:DNA Modification Methylases / Q000032:analysis*; D015342:DNA Probes; D015257:DNA-Cytosine Methylases / Q000032:analysis; D053768:Metal Nanoparticles; D012834:Silver; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D015342:DNA Probes; D012834:Silver; D015254:DNA Modification Methylases; C081573:DNA modification methylase SssI; D015257:DNA-Cytosine Methylases
keywords: DNA-methylation; Hybridization chain reaction (HCR); Sensing; Silver nanoparticles (AgNPs); Surface-enhanced Raman spectroscopic (SRES)