title: Compact characterization of liquid absorption and emission spectra using linear variable filters integrated with a CMOS imaging camera.
abstract: A compact analysis platform for detecting liquid absorption and emission spectra using a set of optical linear variable filters atop a CMOS image sensor is presented. The working spectral range of the analysis platform can be extended without a reduction in spectral resolution by utilizing multiple linear variable filters with different wavelength ranges on the same CMOS sensor. With optical setup reconfiguration, its capability to measure both absorption and fluorescence emission is demonstrated. Quantitative detection of fluorescence emission down to 0.28 nM for quantum dot dispersions and 32 ng/mL for near-infrared dyes has been demonstrated on a single platform over a wide spectral range, as well as an absorption-based water quality test, showing the versatility of the system across liquid solutions for different emission and absorption bands. Comparison with a commercially available portable spectrometer and an optical spectrum analyzer shows our system has an improved signal-to-noise ratio and acceptable spectral resolution for discrimination of emission spectra, and characterization of colored liquid's absorption characteristics generated by common biomolecular assays. This simple, compact, and versatile analysis platform demonstrates a path towards an integrated optical device that can be utilized for a wide variety of applications in point-of-use testing and point-of-care diagnostics.
authors.affiliation: Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Micro and Nanotechnology Laboratory, 208 North Wright Street, Urbana, IL, USA.|School of Electronic and Information Engineering Beihang University, 37 Xueyuan Road, Beijing, China.
authors.forename: Yuhang
authors.initials: Y
authors.lastname: Wan
authors.affiliation: Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Micro and Nanotechnology Laboratory, 208 North Wright Street, Urbana, IL, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Carlson
authors.affiliation: Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Micro and Nanotechnology Laboratory, 208 North Wright Street, Urbana, IL, USA.
authors.forename: Benjamin A
authors.initials: BA
authors.lastname: Kesler
authors.affiliation: Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Micro and Nanotechnology Laboratory, 208 North Wright Street, Urbana, IL, USA.|School of Mechanical Science and Engineering Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Wang
authors.initials: W
authors.lastname: Peng
authors.affiliation: Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Micro and Nanotechnology Laboratory, 208 North Wright Street, Urbana, IL, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Su
authors.affiliation: Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Micro and Nanotechnology Laboratory, 208 North Wright Street, Urbana, IL, USA.
authors.forename: Saoud A
authors.initials: SA
authors.lastname: Al-Mulla
authors.affiliation: Department of Bioengineering University of Illinois at Urbana-Champaign Micro and Nanotechnology Laboratory, 208 North Wright Street, Urbana, IL, USA.
authors.forename: Sung Jun
authors.initials: SJ
authors.lastname: Lim
authors.affiliation: Department of Bioengineering University of Illinois at Urbana-Champaign Micro and Nanotechnology Laboratory, 208 North Wright Street, Urbana, IL, USA.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Smith
authors.affiliation: Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Micro and Nanotechnology Laboratory, 208 North Wright Street, Urbana, IL, USA.
authors.forename: John M
authors.initials: JM
authors.lastname: Dallesasse
authors.affiliation: Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Micro and Nanotechnology Laboratory, 208 North Wright Street, Urbana, IL, USA.|Department of Bioengineering University of Illinois at Urbana-Champaign Micro and Nanotechnology Laboratory, 208 North Wright Street, Urbana, IL, USA.
authors.forename: Brian T
authors.initials: BT
authors.lastname: Cunningham