title: Silver and gold enhancement methods for lateral flow immunoassays.
abstract: Sensitivity is the main concern at the development of rapid test by lateral flow immunoassays. On the other hand, low limits of detection are often required at medical diagnostics and other field of analysis. To overcome this drawback, several enhancement protocols have been described. In this paper, we have selected different silver enhancement methods and one dual gold conjugation, and we critically compared the amplification produced when applied to a gold-nanoparticle based lateral flow immunoassay for the detection of prostate specific antigen (PSA). The highest amplification was obtained by using an immersion method based on a solution of silver nitrate and hydroquinone/citrate buffer in proportion 1:1. Under these conditions, the system is capable of detecting PSA within 20 min at levels as low as 0.1 ng/mL, with a 3-fold sensitivity improvement.
authors.affiliation: Departamento de Química Física y Analítica, Universidad de Oviedo, Julián Clavería 8, 33006 Oviedo, Spain.
authors.forename: Myriam Oliveira
authors.initials: MO
authors.lastname: Rodríguez
authors.affiliation: Departamento de Química Física y Analítica, Universidad de Oviedo, Julián Clavería 8, 33006 Oviedo, Spain.
authors.forename: Lucía Blanco
authors.initials: LB
authors.lastname: Covián
authors.affiliation: Departamento de Química Física y Analítica, Universidad de Oviedo, Julián Clavería 8, 33006 Oviedo, Spain.
authors.forename: Agustín Costa
authors.initials: AC
authors.lastname: García
authors.affiliation: Departamento de Química Física y Analítica, Universidad de Oviedo, Julián Clavería 8, 33006 Oviedo, Spain. Electronic address: cblanco@uniovi.es.
authors.forename: Maria Carmen
authors.initials: MC
authors.lastname: Blanco-López
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods* / Q000592:standards; D002417:Cattle; D006046:Gold / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000379:methods / Q000592:standards; D008297:Male; D017430:Prostate-Specific Antigen / Q000032:analysis*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D012834:Silver / Q000737:chemistry*
chemical_list: D012710:Serum Albumin, Bovine; D012834:Silver; D006046:Gold; D017430:Prostate-Specific Antigen
keywords: Dual gold conjugate; Enhancement procedures; Lateral Flow Immunoassay Dipstick; Silver enhancement