A thionine-based reversible redox sensor in a sequential injection system

• Type: Article in International Scientific Journal
• Date: 2010

Authors

Marieta L C Passos (Author) Other; Lucia L M F S Saraiva (Author) FFUP; Jose L F C Lima (Author) FFUP

Journal

Title: Analytica Chimica Acta

Vol. 668 No. 1

Pages: 41-46

ISSN: 0003-2670

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 7 Citations

Scopus - 8 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

CORDIS: Health sciences

Other information

Authenticus ID: P-003-6NF

DOI: 10.1016/j.aca.2010.01.060

Resumo (PT): Chemistry and regarding the need for lower reagent consumption with improved analytical performance, an automatic methodology with a flow-through optosensor incorporating solid-phase spectrophotometric detection was developed. The sensor used in this work was based on the redox state of thionine whose oxidized form is blue and reduced form is colorless with monitoring carried out at 621 nm. This redox indicator was immobilized on gel beads and subsequently packed into a flow-through cell. It was then assembled into a sequential injection system and was shown to be an excellent alternative to monitor enzymatic redox reactions automatically as the redox catalysis is performed by glucose dehydrogenase. This enzyme is a representative dehydrogenase enzyme and uses NAD+ as cofactor, promoting the oxidation of glucose to glucono-lactone and reduction of NAD+ to NADH. The produced NADH promotes color depletion on the surface of the sensor. The calibration graph for glucose was linear between 5.74 × 10−4 and 2.00 × 10−3 mol L−1 and detection limit was 1.72 × 10−4 mol L−1. Glucose concentration in different samples including sera, salines, perfusion solutions, powder for preparing oral solutions and solutions for hemodialysis was determined. The method proved to be reproducible with a RSD < 5% for glucose determinations. <br> <br> Keywords: Sequential injection analysis; Glucose; Glucose dehydrogenase; Redox sensor; Immobilized thionine; Solid-phase spectrophotometry <br> <a target="_blank" href="http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TF4-4YB5M6D-8&_user=2460038&_coverDate=05%2F23%2F2010&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000057398&_version=1&_urlVersion=0&_userid=2460038&md5=bf38262721aafd7515d128a92a0dfcfd"> Texto integral </a> <br> <br>

Abstract (EN): According to the current demands of Green Analytical Chemistry and regarding the need for lower reagent consumption with improved analytical performance, an automatic methodology with a flow-through optosensor incorporating solid-phase spectrophotometric detection was developed. The sensor used in this work was based on the redox state of thionine whose oxidized form is blue and reduced form is colorless with monitoring carried out at 621 nm. This redox indicator was immobilized on gel beads and subsequently packed into a flow-through cell. It was then assembled into a sequential injection system and was shown to be an excellent alternative to monitor enzymatic redox reactions automatically as the redox catalysis is performed by glucose dehydrogenase. This enzyme is a representative dehydrogenase enzyme and uses NAD as cofactor, promoting the oxidation of glucose to glucono-lactone and reduction of NAD(+) to NADH. The produced NADH promotes color depletion on the surface of the sensor. The calibration graph for glucose was linear between 5.74 x 10(-4) and 2.00 x 10(-3) mol L(-1) and detection limit was 1.72 x 10(-4) mol L(-1). Glucose concentration in different samples including sera, salines, perfusion solutions, powder for preparing oral solutions and solutions for hemoclialysis was determined. The method proved to be reproducible with a RSD <5% for glucose determinations. (C) 2010 Elsevier B.V. All rights reserved.

Language: English

Type (Professor's evaluation): Scientific

Notes: autor para correspondência