title: Ultrasensitive electrogenerated chemiluminescent DNA-based biosensing switch for the determination of bleomycin.
abstract: An ultrasensitive electrogenerated chemiluminescent (ECL) DNA-based biosensing switch for the determination of bleomycin (BLM) was developed based on Fe(II) · BLM-mediated hairpin DNA strand cleavage and a structure-switching ECL-dequenching mechanism. A thiolated ss-DNA was used as a substrate for BLMs: one terminus was tethered onto an electrode surface, and the other terminus was labelled with the ECL quencher ferrocene to form a hairpin structure. This thiolated ss-DNA self-assembled on to the tris(2,2'-bipyridine)ruthenium-gold nanoparticle composite modified gold electrode. In the presence of Fe(II) · BLM, the ECL DNA biosensing switch undergoes an irreversible cleavage event that can trigger a significant increase in ECL intensity. The relationship of ECL intensity and the concentration of BLMs was found to be linear in the range of 5 fM - 5000 fM with a detection limit of 2 fM. This work demonstrates that the design of a highly sensitive ECL DNA-based biosensing switch that uses the sequence selectivity of DNA cleavage mediated by the antitumor drug BLM in combination with a chemical quencher, such as ferrocene, to quench ECL signal(s), offers a promising approach for the determination of ultratrace amounts of antitumor drugs.
authors.affiliation: Institute of Analytical Science, Northwest University, Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry, Xi'an, Shaanxi 710069, China. yanli@nwu.edu.cn
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Cancan
authors.initials: C
authors.lastname: Huang
authors.forename: Jianbin
authors.initials: J
authors.lastname: Zheng
authors.forename: Honglan
authors.initials: H
authors.lastname: Qi
mesh_terms: D015374:Biosensing Techniques; D001761:Bleomycin / Q000032:analysis*; D004277:DNA, Single-Stranded / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D004563:Electrochemistry; D005296:Ferrous Compounds / Q000737:chemistry*; D006046:Gold / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D008163:Luminescent Measurements; D053768:Metal Nanoparticles / Q000737:chemistry; D000075163:Metallocenes; D053761:Nanocomposites / Q000737:chemistry; D012428:Ruthenium / Q000737:chemistry; D044967:Serum / Q000737:chemistry
chemical_list: D004277:DNA, Single-Stranded; D005296:Ferrous Compounds; D000075163:Metallocenes; D001761:Bleomycin; D006046:Gold; D012428:Ruthenium; C004998:ferrocene