title: Hybrid detection of target sequence DNA based on phosphorescence resonance energy transfer.
abstract: The severe background fluorescence and scattering light of real biological samples or environmental samples largely reduce the sensitivity and accuracy of fluorescence resonance energy transfer sensors based on fluorescent quantum dots (QDs). To solve this problem, we designed a novel target sequence DNA biosensor based on phosphorescent resonance energy transfer (PRET). This sensor relied on Mn-doped ZnS (Mn-ZnS) room-temperature phosphorescence (RTP) QDs/poly-(diallyldimethylammonium chloride) (PDADMAC) nanocomposite (QDs+) as the energy donor and the single-strand DNA-ROX as the energy receptor. Thereby, an RTP biosensor was built and used to quantitatively detect target sequence DNA. This biosensor had a detection limit of 0.16nM and a linear range of 0.5-20nM for target sequence DNA. The dependence on RTP of QDs effectively avoided the interference from background fluorescence and scattering light in biological samples. Moreover, this sensor did not need sample pretreatment. Thus, this sensor compared with FRET is more feasible for quantitative detection of target sequence DNA in biological samples. Interestingly, the QDs+nanocomposite prolonged the phosphorescence lifetime of Mn-ZnS QDs by 2.6 times to 4.94ms, which was 5-6 magnitude-order larger than that of fluorescent QDs. Thus, this sensor largely improves the optical properties of QDs and permits chemical reactions at a long enough time scale.
authors.affiliation: Shanxi Normal University, Linfen 041004, PR China. Electronic address: mym8207@126.com.
authors.forename: Yanming
authors.initials: Y
authors.lastname: Miao
authors.affiliation: Shanxi Normal University, Linfen 041004, PR China.
authors.forename: Jinzhi
authors.initials: J
authors.lastname: Lv
authors.affiliation: Shanxi Normal University, Linfen 041004, PR China. Electronic address: gqyan2013@163.com.
authors.forename: Guiqin
authors.initials: G
authors.lastname: Yan
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D004247:DNA / Q000737:chemistry / Q000302:isolation & purification*; D004277:DNA, Single-Stranded / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods; D057230:Limit of Detection; D008163:Luminescent Measurements / Q000379:methods*; D008345:Manganese / Q000737:chemistry; D053761:Nanocomposites / Q000737:chemistry; D045663:Quantum Dots / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D004277:DNA, Single-Stranded; D013440:Sulfides; D017967:Zinc Compounds; D008345:Manganese; D004247:DNA; C031238:zinc sulfide
keywords: Phosphorescence resonance energy transfer; Quantum dots; Target sequence DNA