title: A sensitive quantum dots-based "OFF-ON" fluorescent sensor for ruthenium anticancer drugs and ctDNA.
abstract: In this contribution, a simple and sensitive fluorescent sensor for the determination of both the three ruthenium anticancer drugs (1 to 3) and calf thymus DNA (ctDNA) was established based on the CdTe quantum dots (QDs) fluorescence "OFF-ON" mode. Under the experimental conditions, the fluorescence of CdTe QDs can be effectively quenched by ruthenium anticancer drugs because of the surface binding of these drugs on CdTe QDs and the subsequent photoinduced electron transfer (PET) process from CdTe QDs to ruthenium anticancer drugs, which render the system into fluorescence "OFF" status. The system can then be "ON" after the addition of ctDNA which brought the restoration of CdTe QDs fluorescence intensity, since ruthenium anticancer drugs broke away from the surface of CdTe QDs and inserted into double helix structure of ctDNA. The fluorescence quenching effect of the CdTe QDs-ruthenium anticancer drugs systems was mainly concentration dependent, which could be used to detect three ruthenium anticancer drugs. The limits of detection were 5.5 × 10(-8) M for ruthenium anticancer drug 1, 7.0 × 10(-8) M for ruthenium anticancer drug 2, and 7.9× 10(-8) M for ruthenium anticancer drug 3, respectively. The relative restored fluorescence intensity was directly proportional to the concentration of ctDNA in the range of 1.0 × 10(-8) M ∼ 3.0 × 10(-7) M, with a correlation coefficient (R) of 0.9983 and a limit of detection of 1.1 × 10(-9) M. The relative standard deviation (RSD) for 1.5 × 10(-7) M ctDNA was 1.5% (n = 5). There was almost no interference to some common chemical compounds, nucleotides, amino acids, and proteins. The proposed method was applied to the determination of ctDNA in three synthetic samples with satisfactory results. The possible reaction mechanism of CdTe QDs fluorescence "OFF-ON" was further investigated. This simple and sensitive approach possessed some potential applications in the investigation of interaction between drug molecules and DNA.
authors.affiliation: College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001, PR China. Electronic address: huangs@whu.edu.cn.
authors.forename: Shan
authors.initials: S
authors.lastname: Huang
authors.affiliation: College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001, PR China.
authors.forename: Fawei
authors.initials: F
authors.lastname: Zhu
authors.affiliation: College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001, PR China.
authors.forename: Hangna
authors.initials: H
authors.lastname: Qiu
authors.affiliation: College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001, PR China. Electronic address: qi.xiao@whu.edu.cn.
authors.forename: Qi
authors.initials: Q
authors.lastname: Xiao
authors.affiliation: College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001, PR China.
authors.forename: Quan
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001, PR China. Electronic address: suwmail@163.com.
authors.forename: Wei
authors.initials: W
authors.lastname: Su
authors.affiliation: Key Laboratory of Beibu Gulf Environment Change and Resources Utilization (Guangxi Teachers Education University), Ministry of Education, China.
authors.forename: Baoqing
authors.initials: B
authors.lastname: Hu
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000032:analysis* / Q000494:pharmacology; D015374:Biosensing Techniques / Q000379:methods*; D019187:Cadmium Compounds / Q000737:chemistry; D002417:Cattle; D004247:DNA / Q000032:analysis*; D005453:Fluorescence; D016014:Linear Models; D045663:Quantum Dots / Q000737:chemistry*; D012428:Ruthenium / Q000032:analysis* / Q000494:pharmacology; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013691:Tellurium / Q000737:chemistry
chemical_list: D000970:Antineoplastic Agents; D019187:Cadmium Compounds; D012428:Ruthenium; D004247:DNA; C427203:calf thymus DNA; D013691:Tellurium; C028337:cadmium telluride
keywords: CdTe quantum dots; ctDNA; fluorescent sensor; photoinduced electron transfer; ruthenium anticancer drugs