title: Low level epifluorescent detection of nanoparticles and DNA on dielectrophoretic microarrays.
abstract: Common epifluorescent microscopy lacks the sensitivity to detect low levels of analytes directly in clinical samples, such as drug delivery nanoparticles or disease related DNA biomarkers. Advanced systems such as confocal microscopes may improve detection, but several factors limit their applications. This study now demonstrates that combining an epifluorescent microscope with a dielectrophoretic (DEP) microelectrode array device enables the detection of nanoparticles and DNA biomarkers at clinically relevant levels. Using DEP microarray devices, nanoparticles and DNA biomarkers are rapidly isolated and concentrated onto specific microscopic locations where they are easily detected by epifluorescent microscopy. In this study, 40nm nanoparticles were detected down to 2-3 × 10(3) /ul levels and DNA was detected down to the 200 pg/ml level. The synergy of epifluorescent microscopy and DEP microarray devices provides a new paradigm for DNA biomarker diagnostics and the monitoring of drug delivery nanoparticle concentrations.
authors: University of California, San Diego, Department of Electrical and Computer Engineering, USA.
authors: James P
authors: JP
authors: McCanna
authors: Avery
authors: A
authors: Sonnenberg
authors: Michael J
authors: MJ
authors: Heller
mesh_terms: D000465:Algorithms; D015415:Biomarkers / Q000737:chemistry; D002021:Buffers; D003198:Computer Simulation; D004247:DNA / Q000737:chemistry; D016503:Drug Delivery Systems; D004566:Electrodes; D004586:Electrophoresis; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D008164:Luminescent Proteins / Q000737:chemistry; D046228:Microarray Analysis / Q000379:methods*; D008856:Microscopy, Fluorescence / Q000295:instrumentation* / Q000379:methods; D053758:Nanoparticles / Q000737:chemistry; D000097573:Red Fluorescent Protein
chemical_list: D015415:Biomarkers; D002021:Buffers; D004247:DNA; D005456:Fluorescent Dyes; D008164:Luminescent Proteins; D000097573:Red Fluorescent Protein
keywords: DNA; blood; dielectrophoresis; epifluorescent microscope; microelectrode array; nanoparticles