NIOSHTIC-2 Publications Search

Electrophoretic build-up of multi nanoparticle array for a highly sensitive immunoassay.

Han J-H; Kim H-J; Sudheendra L; Hass EA; Gee SJ; Hammock BD; Kennedy IM

Biosens Bioelectron 2013 Mar; 41:302-308

https://doi.org/10.1016/j.bios.2012.08.042

20042671

One of the challenges in shrinking immunoassays to smaller sizes is to immobilize the biological molecules to nanometer-scaled spots.To overcome this complication, we have employed a particle- based immunoassay to create a nanostructured platform with a regular array of sensing elements. The technique makes use of an electrophoretic particle entrapment system (EPES) to immobilize nanoparticles that are coated with biological reagents into wells using a very small trapping potential. To provide useful information for controlling the trapping force and optimal design of the nanoarray, electrophoretic trapping of a nanoparticle was modeled numerically. The trapping efficiency, defined as the fraction of wells occupied by a single particle, was 91%. The performance of the array was demonstrated with a competitive immunoassay for a small molecule analyte, 3-phenoxybenzoic acid(214.2g mole-1). The limit of detection determined with a basic fluorescence microscope was 0.006 ug l-1 (30 pM); this represented a sixteen-fold improvement in sensitivity compared to a standard 96-wellplate-based ELISA; the improvement was attributed to the small size of the sample volume and the presence of light diffraction among factors unique to this structure. The EPES/nanoarray system promises to offer a new standard in applications that require portable, point-of-care and real-time monitoring with high sensitivity.

Biological-function; Molecular-biology; Molecular-structure; Nanotechnology; Particulates; Models; Author Keywords: Nanoarray; Immunoassay; Electrophoretic particle entrapment system; 3-phenoxybenzoic acid (3-PBA)

Ian M. Kennedy, Department of Mechanical and Aerospace Engineering, University of California, Davis, California, CA 95616, USA

BBIOE4

3739-38-6

20130315

Journal Article

imkennedy@ucdavis.edu

Cooperative Agreement; Agriculture

2013

Cooperative-Agreement-Number-U54-OH-007550; B20130612

0956-5663

Agriculture, Forestry and Fishing

Biosensors and Bioelectronics

CA

University of California - Davis