title: A DNA biosensor based on the detection of doxorubicin-conjugated Ag nanoparticle labels using solid-state voltammetry.
abstract: This report describes an electrochemical biosensor for the detection of short DNA oligonucleotide of the avian flu virus H5N1 with sequence 5'-CCA AGC AAC AGA CTC AAA-3'. To fabricate this DNA biosensor, a gold (Au) electrode surface was modified with thiolated DNA probes with a sequence complementary to the target DNA. This modified Au electrode was incubated in a buffer solution containing the target DNA to form double-stranded DNA (ds-DNA) through hybridization. The ds-DNA on the electrode surface was then labeled with silver nanoparticles conjugated with a well-known DNA intercalator, doxorubicin. By performing cyclic voltammetry in an aqueous KCl solution (0.3M), the silver nanoparticle labels were detected as a result of the highly characteristic solid-state Ag/AgCl redox process. The signal obtained was subsequently used to quantify the amount of DNA. A detection limit of 1 pM has been achieved with this new DNA biosensor.
authors: Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, Singapore 138669, Singapore.
authors: Boon Ping
authors: BP
authors: Ting
authors: Jie
authors: J
authors: Zhang
authors: Zhiqiang
authors: Z
authors: Gao
authors: Jackie Y
authors: JY
authors: Ying
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D004279:DNA, Viral / Q000032:analysis* / Q000235:genetics; D004317:Doxorubicin / Q000737:chemistry*; D004563:Electrochemistry / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007118:Immunoassay; D053124:Influenza A Virus, H5N1 Subtype / Q000235:genetics*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation*; D012666:Semiconductors; D012834:Silver / Q000737:chemistry; D013194:Staining and Labeling; D014159:Transducers
chemical_list: D004279:DNA, Viral; D012834:Silver; D004317:Doxorubicin