title: Multifunctional analytical platform on a paper strip: separation, preconcentration, and subattomolar detection.
abstract: We report a plasmonic paper-based analytical platform with functional versatility and subattomolar (<10(-18) M) detection limit using surface-enhanced Raman scattering as a transduction method. The microfluidic paper-based analytical device (μPAD) is made with a lithography-free process by a simple cut and drop method. Complex samples are separated by a surface chemical gradient created by differential polyelectrolyte coating of the paper. The μPAD with a starlike shape is designed to enable liquid handling by lateral flow without microchannel patterning. This design generates a rapid capillary-driven flow capable of dragging liquid samples as well as gold nanorods into a single cellulose microfiber, thereby providing an extremely preconcentrated and optically active detection spot.
authors: Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, St. Louis, Missouri 63130, United States.
authors: Abdennour
authors: A
authors: Abbas
authors: Andrew
authors: A
authors: Brimer
authors: Joseph M
authors: JM
authors: Slocik
authors: Limei
authors: L
authors: Tian
authors: Rajesh R
authors: RR
authors: Naik
authors: Srikanth
authors: S
authors: Singamaneni
mesh_terms: D002338:Carotenoids / Q000032:analysis; D005591:Chemical Fractionation / Q000295:instrumentation / Q000379:methods*; D002734:Chlorophyll / Q000032:analysis; D005456:Fluorescent Dyes; D006046:Gold / Q000737:chemistry; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D046529:Microscopy, Electron, Transmission; D043942:Nanotubes / Q000737:chemistry / Q000648:ultrastructure; D010209:Paper; D010936:Plant Extracts / Q000737:chemistry*; D011073:Polyamines / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013059:Spectrum Analysis, Raman; D018724:Spinacia oleracea / Q000737:chemistry*; D013451:Sulfonic Acids / Q000737:chemistry
chemical_list: D005456:Fluorescent Dyes; D010936:Plant Extracts; D011073:Polyamines; D011108:Polymers; D013451:Sulfonic Acids; D002734:Chlorophyll; C063994:polyallylamine; D002338:Carotenoids; D006046:Gold; C077114:styrenesulfonic acid polymer