title: Smartphone instrument for portable enzyme-linked immunosorbent assays.
abstract: We demonstrate the utilization of a smartphone camera as a spectrometer that is capable of measuring Enzyme Linked Immunosorbent Assays (ELISA) at biologically-relevant concentrations with the aid of a custom cradle that aligns a diffraction grating and a collimating lens between a light source and the imaging sensor. Two example biomarkers are assayed using conventional ELISA protocols: IL-6, a protein used diagnostically for several types of cancer, and Ara h 1, one of the principle peanut allergens. In addition to the demonstration of limits of detection at medically-relevant concentrations, a screening of various cookies was completed to measure levels of peanut cross-contamination in local bakeries. The results demonstrate the utility of the instrument for quantitatively performing broad classes of homogeneous colorimetric assays, in which the endpoint readout is the color change of a liquid sample.
authors.affiliation: Department of Bioengineering, Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, 208 N. Wright Street, Urbana, IL, 61801, USA.
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Long
authors.affiliation: Department of Electrical and Computer Engineering, Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, 208 N. Wright Street, Urbana, IL, 61801, USA.
authors.forename: Hojeong
authors.initials: H
authors.lastname: Yu
authors.affiliation: Department of Bioengineering, Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, 208 N. Wright Street, Urbana, IL, 61801, USA ; Department of Electrical and Computer Engineering, Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, 208 N. Wright Street, Urbana, IL, 61801, USA.
authors.forename: Brian T
authors.initials: BT
authors.lastname: Cunningham
keywords: (280.1415) Biological sensing and sensors; (280.4788) Optical sensing and sensors; (300.1030) Absorption