title: Flexible microfabricated film sensors for the in situ quantum dot-based voltammetric detection of DNA hybridization in microwells.
abstract: A new flexible miniaturized integrated device was microfabricated for the in situ ultrasensitive voltammetric determination of DNA mutation in a microwell format, using quantum dots (QDs) labels. The integrated device consisted of thin Bi, Ag, and Pt films (serving as the working, reference, and counter electrode, respectively) deposited by sputtering on a flexible polyimide substrate. A DNA assay was employed in microwell format, where an immobilized complementary oligonucleotide probe hybridized with the biotinylated target oligonucleotide followed by reaction with streptavidin-conjugated PbS QDs. After the acidic dissolution of the QDs, the flexible sensor was rolled and inserted into the microwell and the Pb(II) released was determined in situ by anodic stripping voltammetry. Since the analysis took place directly in the microwell, the volume of the working solution was only 100 μL and the target DNA could be detected at a concentration down to 1.1 fmol L(-1). The proposed flexible microdevice addresses the restrictions of conventional rigid electrodes while it provides a low cost integrated transducer for the ultrasensitive detection of important biomolecules.
authors.affiliation: Laboratory of Analytical Chemistry, Department of Chemistry, University of Ioannina , Ioannina, 45110, Greece.
authors.forename: Christos
authors.initials: C
authors.lastname: Kokkinos
authors.forename: Anastasios
authors.initials: A
authors.lastname: Economou
authors.forename: Thanasis
authors.initials: T
authors.lastname: Speliotis
authors.forename: Panagiota
authors.initials: P
authors.lastname: Petrou
authors.forename: Sotirios
authors.initials: S
authors.lastname: Kakabakos
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D019921:Biotinylation; D004247:DNA / Q000032:analysis* / Q000235:genetics; D004563:Electrochemistry; D004566:Electrodes; D006801:Humans; D057230:Limit of Detection; D008670:Metals / Q000737:chemistry; D055616:Microtechnology / Q000295:instrumentation / Q000379:methods*; D009154:Mutation / Q000235:genetics; D009693:Nucleic Acid Hybridization / Q000379:methods*; D051096:Proto-Oncogene Proteins c-ret / Q000235:genetics; D045663:Quantum Dots; D019809:Streptavidin / Q000378:metabolism
chemical_list: D008670:Metals; D004247:DNA; D019809:Streptavidin; D051096:Proto-Oncogene Proteins c-ret; C099282:RET protein, human