title: "Turn-off-on" fluorescent sensor for (N-methyl-4-pyridyl) porphyrin -DNA and G-quadruplex interactions based on ZnCdSe quantum dots.
abstract: As a new detection model, the reversible fluorescence "turn-off-on" sensor based on quantum dots (QDs) has already been successfully employed in the detections of many biochemical materials, especially in the researches on the interactions between anticancer drugs. The previous studies, however, mainly focused on simple-structured oligonucleotides and Calf thymus DNA. G-quadruplex, an important target for anti-cancer drug with special secondary structure, has been stimulating increasing research interests. In this paper, we report a new detection method based on the fluorescence "turn-off-on" model with water-soluble ZnCdSe QDs as the fluorescent probe, to analyze the interactions between anticancer drug (N-methyl-4-pyridyl) porphyrin (TMPyP) and nucleic acid, especially the G-quadruplex. The fluorescence of QDs can be quenched by TMPyP via photo-induced electron transfer and fluorescence resonance energy transfer, while on the other hand, the combination between TMPyP and G-quadruplex releases QDs from their quenchers and thus recovers the fluorescence. Most importantly, the fluorescence "turn-off-on" model has been employed, for the first time, to analyze the impacts of special factors on the interaction between TMPyP and G-quadruplex. The excellent selectivity of the system has been verified in the studies of the interactions between TMPyP and different DNAs (double-stranded DNA, single-stranded G-quadruplex, and different types of G-quadruplexes) in Na(+) or K(+)-containing buffer.
authors: College of Pharmacy, South-Central University for Nationalities, Wuhan 430074, PR China.
authors: Dan
authors: D
authors: Zhao
authors: College of Pharmacy, South-Central University for Nationalities, Wuhan 430074, PR China.
authors: Yao
authors: Y
authors: Fan
authors: College of Pharmacy, South-Central University for Nationalities, Wuhan 430074, PR China.
authors: Fang
authors: F
authors: Gao
authors: College of Pharmacy, South-Central University for Nationalities, Wuhan 430074, PR China. Electronic address: tmyang@mail.scuec.edu.cn.
authors: Tian-ming
authors: TM
authors: Yang
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D015374:Biosensing Techniques / Q000379:methods; D019187:Cadmium Compounds / Q000737:chemistry*; D002417:Cattle; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry*; D054856:G-Quadruplexes / Q000187:drug effects*; D006801:Humans; D011166:Porphyrins / Q000494:pharmacology*; D045663:Quantum Dots / Q000737:chemistry*; D018036:Selenium Compounds / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D000970:Antineoplastic Agents; D019187:Cadmium Compounds; D005456:Fluorescent Dyes; D011166:Porphyrins; D018036:Selenium Compounds; D017967:Zinc Compounds; C021096:tetra(4-N-methylpyridyl)porphine; D004247:DNA; C427203:calf thymus DNA; C058667:cadmium selenide; C044696:zinc selenide
keywords: (N-Methyl-4-pyridyl) porphyrin; G-quadruplex; Quantum dots; Turn-off-on