title: Numerical study of in situ preconcentration for rapid and sensitive nanoparticle detection.
abstract: This paper presents a numerical study of a preconcentrator design that can effectively increase the binding rate at the sensor in a real time manner. The particle enrichment is realized by the ac electrothermal (ACET) effect, which induces fluid movement to carry nanoparticles toward the sensor. The ACET is the only electrical method to manipulate a biological sample of medium to high ionic strength (>0.1 Sm, e.g., 0.06x phosphate buffered saline). The preconcentrator consists of a pair of electrodes striding over the sensor, simple to implement as it is electrically controlled. This preconcentrator design is compatible and can be readily integrated with many types of micro- to nanosensors. By applying an ac signal over the electrodes, local vortices will generate a large velocity perpendicular to the reaction surface, which enhances transport of analytes toward the sensor. Our simulation shows that the binding rate at the sensor surface is greatly enhanced. Our study also shows that the collection of analytes will be affected by various parameters such as channel height, inlet velocity, and sensor size, and our results will provide guidance in optimization of the preconcentrator design.
authors.affiliation: Department of Electrical Engineering and Computer Science, The University of Tennessee, Knoxville, Tennessee 37996, USA.
authors.forename: Kai
authors.initials: K
authors.lastname: Yang
authors.forename: Jie
authors.initials: J
authors.lastname: Wu
references.citation: IET Nanobiotechnol. 2007 Jun;1(3):36-43
references.pmid: 17506595
references.citation: Nano Lett. 2008 Oct;8(10):3233-7
references.pmid: 18788786
references.citation: Lab Chip. 2005 Dec;5(12):1366-73
references.pmid: 16286967
references.citation: Nat Biotechnol. 2008 Apr;26(4):417-26
references.pmid: 18392027
references.citation: Langmuir. 2005 Jul 5;21(14):6603-12
references.pmid: 15982074
references.citation: Lab Chip. 2007 Nov;7(11):1553-9
references.pmid: 17960285
references.citation: Anal Chem. 2004 Dec 1;76(23):6908-14
references.pmid: 15571340
references.citation: Nano Lett. 2005 Apr;5(4):803-7
references.pmid: 15826132
references.citation: J Math Biol. 1999 Dec;39(6):533-61
references.pmid: 10672509