title: Electrochemical lateral flow immunosensor for detection and quantification of dengue NS1 protein.
abstract: An Electrochemical Lateral Flow Immunosensor (ELFI) is developed combining screen-printed gold electrodes (SPGE) enabling quantification together with the convenience of a lateral flow test strip. A cellulose glassy fiber paper conjugate pad retains the marker immunoelectroactive nanobeads which will bind to the target analyte of interest. The specific immunorecognition event continues to occur along the lateral flow bed until reaching the SPGE-capture antibodies at the end of the cellulosic lateral flow strip. The rationale of the immunoassay consists in the analyte antigen NS1 protein being captured selectively and specifically by the dengue NS1 antibody conjugated onto the immunonanobeads thus forming an immunocomplex. With the aid of a running buffer, the immunocomplexes flow and reach the immuno-conjugated electrode surface and form specific sandwich-type detection due to specific, molecular recognition, while unbound beads move along past the electrodes. The successful sandwich immunocomplex formation is then recorded electrochemically. Specific detection of NS1 is translated into an electrochemical signal contributed by a redox label present on the bead-immobilized detection dengue NS1 antibody while a proportional increase of faradic current is observed with increase in analyte NS1 protein concentration. The first generation ELFI prototype is simply assembled in a cassette and successfully demonstrates wide linear range over a concentration range of 1-25 ng/mL with an ultrasensitive detection limit of 0.5 ng/mL for the qualitative and quantitative detection of analyte dengue NS1 protein.
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, Block N4.1, Nanyang Avenue, Singapore 639798, Singapore; NTU-HUJ-BGU (NEW-CREATE) Programme, 1 CREATE Way, Research Wing, #02-06/08, Singapore 138602, Singapore.
authors.forename: Prima Dewi
authors.initials: PD
authors.lastname: Sinawang
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, Block N4.1, Nanyang Avenue, Singapore 639798, Singapore; NTU-HUJ-BGU (NEW-CREATE) Programme, 1 CREATE Way, Research Wing, #02-06/08, Singapore 138602, Singapore.
authors.forename: Varun
authors.initials: V
authors.lastname: Rai
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, Block N4.1, Nanyang Avenue, Singapore 639798, Singapore; NTU-HUJ-BGU (NEW-CREATE) Programme, 1 CREATE Way, Research Wing, #02-06/08, Singapore 138602, Singapore; Laboratoire de Nanotechnologie et d'Instrumentation Optique, Institute Charles Delaunay, Université de Technologie de Troyes, UMR CNRS 6281, 12 Rue Marie-Curie CS 42060, 10004 Cedex Troyes, France.
authors.forename: Rodica E
authors.initials: RE
authors.lastname: Ionescu
authors.affiliation: School of Materials Science and Engineering, Nanyang Technological University, Block N4.1, Nanyang Avenue, Singapore 639798, Singapore; NTU-HUJ-BGU (NEW-CREATE) Programme, 1 CREATE Way, Research Wing, #02-06/08, Singapore 138602, Singapore; Ben-Gurion University of the Negev, Department of Biotechnology Engineering, PO Box 653, 84105 Beer-Sheva, Israel. Electronic address: rsmarks@bgu.ac.il.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Marks
mesh_terms: D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007118:Immunoassay / Q000295:instrumentation*; D056656:Lab-On-A-Chip Devices; D017361:Viral Nonstructural Proteins / Q000032:analysis*
chemical_list: C082515:NS1 protein, dengue-1 virus; D017361:Viral Nonstructural Proteins
keywords: Cellulose paper; Cyclic voltammetry; Dengue virus DENV NS1 protein; Electrochemical impedance spectroscopy (EIS); Electrochemical lateral flow immunosensor; Gold nanoparticles (AuNPs)