title: Optical paper-based sensor for ascorbic acid quantification using silver nanoparticles.
abstract: In this paper, we demonstrate for the first time the use of silver nanoparticles (AgNPs) for colorimetric ascorbic acid (AA) quantification in a paper-based sensor. This device is constituted by spot tests modified with AgNPs and silver ions bordered by a hydrophobic barrier which provides quantitative and fast analysis of AA. In addition, this device is employed as point-of-care monitoring using a unique drop of the sample. AgNPs paper-based sensor changed from light yellow to gray color after the addition of AA due to nanoparticle growth and clusters formation. The color intensities were altered as a function of AA concentration which were measured by either a scanner or a homemade portable transmittance colorimeter. Under the selected measurement conditions, results presented limit of detection which was comparable to analytical laboratory-based methodologies. In addition, the sensitivity of our sensor was comparable to the standard titration method when real samples were investigated.
authors.affiliation: LNNano - Laboratório Nacional de Nanotecnologia, Centro Nacional de Pesquisa em Energia e Materiais, CEP 13083-970, Campinas, São Paulo, Brazil. Electronic address: daniellecristhina@hotmail.com.
authors.forename: Danielle Cristhina Melo
authors.initials: DC
authors.lastname: Ferreira
authors.affiliation: LNNano - Laboratório Nacional de Nanotecnologia, Centro Nacional de Pesquisa em Energia e Materiais, CEP 13083-970, Campinas, São Paulo, Brazil.
authors.forename: Gabriela Furlan
authors.initials: GF
authors.lastname: Giordano
authors.affiliation: LNNano - Laboratório Nacional de Nanotecnologia, Centro Nacional de Pesquisa em Energia e Materiais, CEP 13083-970, Campinas, São Paulo, Brazil.
authors.forename: Caio César dos Santos Penteado
authors.initials: CC
authors.lastname: Soares
authors.affiliation: LNLS - Laboratório Nacional de Luz Síncrotron, Centro Nacional de Pesquisa em Energia e Materiais, CEP 13083-970, Campinas, São Paulo, Brazil; Instituto de Química, Universidade Estadual de Campinas, CEP 13083-970, Campinas, São Paulo, Brazil.
authors.forename: Jessica Fernanda Afonso
authors.initials: JF
authors.lastname: de Oliveira
authors.affiliation: Pontíficia Universidade Católica de Campinas, Faculdade de Química, CEP 13012-970, Campinas, São Paulo, Brazil.
authors.forename: Renata Kelly
authors.initials: RK
authors.lastname: Mendes
authors.affiliation: LNNano - Laboratório Nacional de Nanotecnologia, Centro Nacional de Pesquisa em Energia e Materiais, CEP 13083-970, Campinas, São Paulo, Brazil.
authors.forename: Maria Helena
authors.initials: MH
authors.lastname: Piazzetta
authors.affiliation: LNNano - Laboratório Nacional de Nanotecnologia, Centro Nacional de Pesquisa em Energia e Materiais, CEP 13083-970, Campinas, São Paulo, Brazil.
authors.forename: Angelo Luiz
authors.initials: AL
authors.lastname: Gobbi
authors.affiliation: LNLS - Laboratório Nacional de Luz Síncrotron, Centro Nacional de Pesquisa em Energia e Materiais, CEP 13083-970, Campinas, São Paulo, Brazil; Instituto de Química, Universidade Estadual de Campinas, CEP 13083-970, Campinas, São Paulo, Brazil. Electronic address: cardosomb@lnls.br.
authors.forename: Mateus Borba
authors.initials: MB
authors.lastname: Cardoso
keywords: Ascorbic acid detection; Colorimetric analysis; Paper-based device; Sensor; Silver nanoparticles