Please use this identifier to cite or link to this item: http://hdl.handle.net/1822/49093

TitleMicrofluidic immunosensor for rapid and highly-sensitive salivary cortisol quantification
Author(s)Pinto, Vânia C.
Sousa, Paulo J.
Catarino, Susana Oliveira
Neves, Margarida Correia
Minas, Graça
KeywordsMicrofluidic immunosensor
Colorimetric detection
Lab-on-a-chip (LOC)
Poly(dimethylsiloxane)
Salivary cortisol
Issue date15-Apr-2017
PublisherElsevier
JournalBiosensors and Bioelectronics
CitationPinto, V., Sousa, P., Catarino, S. O., Correia-Neves, M., & Minas, G. (2017). Microfluidic immunosensor for rapid and highly-sensitive salivary cortisol quantification. Biosensors and Bioelectronics, 90, 308-313
Abstract(s)This paper presents a novel poly(dimethylsiloxane) (PDMS) microfluidic immunosensor that integrates a complementary metal-oxide-semiconductor (CMOS) optical detection system for a rapid and highly-sensitive quantification of salivary cortisol. The simple and non-invasive method of saliva sampling provides an interesting alternative to the blood, allowing a fast sampling at short intervals, relevant for many clinical diagnostic applications. The developed approach is based on the covalent immobilization of a coating antibody (Ab), a polyclonal anti-IgG, onto a treated PDMS surface. The coating Ab binds the capture Ab, an IgG specific for cortisol, allowing its correct orientation. Horseradish peroxidase (HRP)-labelled cortisol is added to compete with the cortisol in the sample, for the capture Ab binding sites. The HRP-labelled cortisol, bonded to the capture Ab, is measured through the HRP enzyme and the tetramethylbenzidine (TMB) substrate reaction. The cortisol quantification is performed by colorimetric detection of HRP-labelled cortisol, through optical absorption at 450 nm, using a CMOS silicon photodiode as the photodetector. Under the developed optimized conditions presented here, e.g., microfluidic channels geometry, immobilization method and immunoassay conditions, the immunosensor shows a linear range of detection between 0.01-20 ng/mL, a limit of detection (LOD) of 18 pg/mL and an analysis time of 35 min, featuring a great potential for point-of-care applications requiring continuous monitoring of the salivary cortisol levels during a circadian cycle.
TypeArticle
URIhttp://hdl.handle.net/1822/49093
DOI10.1016/j.bios.2016.11.067
ISSN0956-5663
Publisher versionhttps://www.sciencedirect.com/science/journal/09565663
Peer-Reviewedyes
AccessOpen access
Appears in Collections:DEI - Artigos em revistas internacionais
ICVS - Artigos em Revistas Internacionais com Referee

Files in This Item:
File Description SizeFormat 
untitled.pdf599,03 kBAdobe PDFView/Open

Partilhe no FacebookPartilhe no TwitterPartilhe no DeliciousPartilhe no LinkedInPartilhe no DiggAdicionar ao Google BookmarksPartilhe no MySpacePartilhe no Orkut
Exporte no formato BibTex mendeley Exporte no formato Endnote Adicione ao seu ORCID