Lateral flow devices for nucleic acid analysis exploiting quantum dots as reporters.
There is a growing interest in the development of biosensors in the form of simple lateral flow devices that enable visual detection of nucleic acid sequences while eliminating several steps required for pipetting, incubation and washing out the excess of reactants. In this work, we present the first dipstick-type nucleic acid biosensors based on quantum dots (QDs) as reporters. The biosensors enable sequence confirmation of the target DNA by hybridization and simple visual detection of the emitted fluorescence under a UV lamp. The 'diagnostic' membrane of the biosensor contains a test zone (TZ) and a control zone (CZ). The CZ always fluoresces in order to confirm the proper function of the biosensor. Fluorescence is emitted from the TZ, only when the specific nucleic acid sequence is present. We have developed two general types of QD-based nucleic acid biosensors, namely, Type I and Type II, in which the TZ consists of either immobilized streptavidin (Type I) or immobilized oligodeoxynucleotides (Type II). The control zone consists of immobilized biotinylated albumin. No purification steps are required prior to the application of the DNA sample on the strip. The QD-based nucleic acid biosensors performed accurately and reproducibly when applied to (a) the visual detection of PCR amplification products and (b) visual genotyping of single nucleotide polymorphisms (SNPs) in human genomic DNA from clinical samples. As low as 1.5 fmol of double-stranded DNA were clearly detected by naked eye and the dynamic range extended to 200 fmol. The %CV were estimated to be 4.3-8.2.
Department of Chemistry, University of Patras, GR-26504 Patras, Greece.
Eleni A
EA
Sapountzi
Department of Chemistry, University of Patras, GR-26504 Patras, Greece.
Sotirios S
SS
Tragoulias
Department of Chemistry, University of Patras, GR-26504 Patras, Greece.
Despina P
DP
Kalogianni
Department of Chemistry, University of Athens, GR-15771 Athens, Greece.
Penelope C
PC
Ioannou
Department of Chemistry, University of Patras, GR-26504 Patras, Greece; Institute of Chemical Engineering and High Temperature Processes, Foundation of Research and Technology Hellas, GR-26504 Patras, Greece. Electronic address: tchrist@upatras.gr.
Theodore K
TK
Christopoulos
D015374:Biosensing Techniques / Q000295:instrumentation; D004247:DNA / Q000032:analysis* / Q000235:genetics; D006801:Humans; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D045663:Quantum Dots; D019809:Streptavidin / Q000737:chemistry
D009838:Oligodeoxyribonucleotides; D004247:DNA; D019809:Streptavidin
Biosensor; Lateral flow; Nanoparticles; Nucleic acids; Quantum dots