title: Quantum-dot biosensor for hybridization and detection of R3500Q mutation of apolipoprotein B-100 gene.
abstract: A quantum-dot electrode system was developed as a transducer surface for covalent immobilization of a designed synthetic ApoB-100 specific probe, DNA hybridization and monitoring of DNA synthesis for the sensitive detection of R3500Q mutation of apolipoprotein B-100 (ApoB-100) gene. CdS-QDs cause an improvement in the fundamental characteristics of the electrode interface, such as its electroactive surface area, diffusion coefficient and electron transfer kinetics. The sensing characteristics of this biosensor offer a suitable potential for detection of target oligonucleotide with a detection limit of 3.4 × 10(-17)M. Also, the electrochemical responses of single-stranded DNA (ssDNA), DNA hybridization and DNA synthesis were investigated using electrochemical impedance spectroscopy (EIS). The extracted genomic DNA was detected based on changes in the charge transfer resistance (RCT) with [Fe(CN)6](3-/4-) as a redox probe. The proposed biosensor can distinguish between the normal sequence and the mutant sequence of ApoB-100 gene, promising a possibility to apply the QD-based biosensor for clinical investigations.
authors.affiliation: Department of Chemistry, Faculty of Science, Yazd University, Yazd 89195-741, Iran. Electronic address: mazloum@yazd.ac.ir.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Mazloum-Ardakani
authors.affiliation: Department of Chemistry, Faculty of Science, Yazd University, Yazd 89195-741, Iran.
authors.forename: Roghayyeh
authors.initials: R
authors.lastname: Aghaei
authors.affiliation: Department of Biology, Faculty of Science, Yazd University, Yazd 89195-741, Iran.
authors.forename: Mohammad Mehdi
authors.initials: MM
authors.lastname: Heidari
mesh_terms: D053299:Apolipoprotein B-100 / Q000235:genetics*; D015374:Biosensing Techniques / Q000295:instrumentation*; D019187:Cadmium Compounds / Q000737:chemistry; D004247:DNA / Q000032:analysis / Q000097:blood / Q000235:genetics*; D004252:DNA Mutational Analysis / Q000295:instrumentation; D058266:Dielectric Spectroscopy; D004566:Electrodes; D006801:Humans; D009693:Nucleic Acid Hybridization; D017354:Point Mutation; D045663:Quantum Dots / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry; D014159:Transducers
chemical_list: D053299:Apolipoprotein B-100; D019187:Cadmium Compounds; D013440:Sulfides; C034939:cadmium sulfide; D004247:DNA
keywords: Apolipoprotein B-100 gene; CdS quantum dot; DNA biosensor; DNA hybridization; Electrochemical impedance spectroscopy