title: A droplet-based microfluidic immunosensor for high efficiency melamine analysis.
abstract: We report a droplet-based microfluidic immunosensor for the rapid and accurate detection of melamine, an organic base that has been implicated in widescale adulteration of food products such as milk. Our melamine assay is based on the competitive reaction between native melamine and a melamine-fluorescein isothiocyanate (FITC) conjugate against an anti-hapten antibody. The adoption of fluorescence polarization, allows the quantification of melamine in a more direct and rapid manner than established heterogeneous methods based on liquid chromatography, mass spectrometry, and enzyme-linked immunosorbent assay (ELISA). The detection protocol provides a limit of detection of 300 ppb, which is below the maximum allowable melamine levels (2.5 ppm) defined by the U.S. Food and Drug Administration and the European Commission to a significant extent.
authors.affiliation: Department of Biochemistry, Chungbuk National University, Cheongju 28644, Republic of Korea. Electronic address: jwchoi21@chungbuk.ac.kr.
authors.forename: Jae-Won
authors.initials: JW
authors.lastname: Choi
authors.affiliation: Department of Biochemistry, Chungbuk National University, Cheongju 28644, Republic of Korea.
authors.forename: Kyong-Mi
authors.initials: KM
authors.lastname: Min
authors.affiliation: Department of Biochemistry, Chungbuk National University, Cheongju 28644, Republic of Korea.
authors.forename: Sundar
authors.initials: S
authors.lastname: Hengoju
authors.affiliation: Department of Biochemistry, Chungbuk National University, Cheongju 28644, Republic of Korea.
authors.forename: Gil-Jung
authors.initials: GJ
authors.lastname: Kim
authors.affiliation: Department of Biochemistry, Chungbuk National University, Cheongju 28644, Republic of Korea.
authors.forename: Soo-Ik
authors.initials: SI
authors.lastname: Chang
authors.affiliation: Department of Chemistry & Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1, 8093 Zürich, Switzerland.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: deMello
authors.affiliation: Department of Bionano Technology, Hanyang University, Ansan 15588, Republic of Korea. Electronic address: jbchoo@hanyang.ac.kr.
authors.forename: Jaebum
authors.initials: J
authors.lastname: Choo
authors.affiliation: Department of Biochemistry, Chungbuk National University, Cheongju 28644, Republic of Korea. Electronic address: hykim@chungbuk.ac.kr.
authors.forename: Hak Yong
authors.initials: HY
authors.lastname: Kim
mesh_terms: D000818:Animals; D015374:Biosensing Techniques; D004797:Enzyme-Linked Immunosorbent Assay; D005504:Food Analysis; D006801:Humans; D044085:Microfluidics; D008892:Milk / Q000737:chemistry; D014227:Triazines / Q000737:chemistry / Q000302:isolation & purification*; D014481:United States; D014486:United States Food and Drug Administration
chemical_list: D014227:Triazines; C011907:melamine
keywords: Droplet-based microfluidics; Fluorescence polarization; Melamine; Milk