title: Use of quantum dots as mass and fluorescence labels in microarray biosensing.
abstract: In this work, we demonstrate the efficacy of a Quantum Dot (QD) mass label strategy to enhance sensitivity in an interferometric technique called interferometric reflectance imaging sensor (IRIS). This biomass detection platform confers the advantage of absolute mass quantification and lower cost, easily implementable equipment. We discuss the advantages of this label when used in parallel with fluorescence detection. QDs represent a unique opportunity to improve sensitivity in both mass-label detection methods due to their large detectable mass, as well as in fluorescence detection, as they fluoresce without quenching. Streptavidin-conjugated QDs (SA-QDs) have been investigated as such a dual-role probe because of their large shape and mass, their 655nm emission peak for fluorescent detection platforms, and their robust insensitivity to photobleaching and quenching. In particular we explored their dual role in a microarrays immunoassay designed to detect antibodies against β-lactoglobulin, a common milk allergen. The SA-QDs formed a large detectable monolayer of 6.2ng/mm(2) in the saturation conditions, a mass signal corroborated by previous studies by Platt et al..
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto di Chimica del Riconoscimento Molecolare, 20131 Milano, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Finetti
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto di Chimica del Riconoscimento Molecolare, 20131 Milano, Italy.
authors.forename: Lauren
authors.initials: L
authors.lastname: Plavisch
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto di Chimica del Riconoscimento Molecolare, 20131 Milano, Italy. Electronic address: marcella.chiari@icrm.cnr.it.
authors.forename: Marcella
authors.initials: M
authors.lastname: Chiari
mesh_terms: D018533:Biomass; D015374:Biosensing Techniques / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry*; D007368:Interferometry; D046228:Microarray Analysis / Q000379:methods*; D008970:Molecular Weight; D019095:Point-of-Care Systems; D045663:Quantum Dots / Q000737:chemistry*; D019809:Streptavidin / Q000737:chemistry
chemical_list: D005456:Fluorescent Dyes; D019809:Streptavidin
keywords: Fluorescence detection; Interferometry; Label-free detection; Mass label; Microarrays; Quantum dots