Construction of effective disposable biosensors for point of care testing of nitrite

TALANTA

卷:142

Article

Monteiro, Tiago^1,2  Rodrigues, Patricia R.²  Goncalves, Ana Luisa²  Moura, Jose J. G.²  Jubete, Elena³  Anorga, Larraitz³  Piknova, Barbora⁴  Schechter, Alan N.⁴  Silveira, Celia M.^2,5  Gabriela Almeida, M.^1,2 

[1] Inst Super Ciencias Saude Egas Moniz, Ctr Invest Interdisciplinar Egas Moniz CiiEM, P-2829511 Caparica, Portugal

[2] Univ Nova Lisboa, Fac Ciencias & Tecnol, REQUIMTE, UCIBIO, P-2829516 Monte De Caparica, Portugal

[3] IK4 CIDETEC, Div Mat, Sensors Unit, Donostia San Sebastian 20009, Spain

[4] NIDDK, Mol Med Branch, NIH, Bethesda, MD 20892 USA

[5] Univ Nova Lisboa, Inst Tecnol Quim & Biol, P-2780157 Oeiras, Portugal

关键词: Point of care testing;    Nitrite;    Cytochrome c nitrite reductase;    Biosensors;    Screen printed electrodes;    Carbon conductive ink;   

DOI  :  10.1016/j.talanta.2015.04.057

来源: Elsevier

【 摘 要 】

In this paper we aim to demonstrate, as a proof-of-concept, the feasibility of the mass production of effective point of care tests for nitrite quantification in environmental, food and clinical samples. Following our previous work on the development of third generation electrochemical biosensors based on the ammonia forming nitrite reductase (ccNiR), herein we reduced the size of the electrodes' system to a miniaturized format, solved the problem of oxygen interference and performed simple quantification assays in real samples. In particular, carbon paste screen printed electrodes (SPE) were coated with a ccNiR/carbon ink composite homogenized in organic solvents and cured at low temperatures. The biocompatibility of these chemical and thermal treatments was evaluated by cyclic voltammetry showing that the catalytic performance was higher with the combination acetone and a 40 degrees C curing temperature. The successful incorporation of the protein in the carbon ink/solvent composite, while remaining catalytically competent, attests for ccNiR's robustness and suitability for application in screen printed based biosensors. Because the direct electrochemical reduction of molecular oxygen occurs when electroanalytical measurements are performed at the negative potentials required to activate ccNiR (ca. - 0.4 V vs Ag/AgCl), an oxygen scavenging system based on the coupling of glucose oxidase and catalase activities was successfully used. This enabled the quantification of nitrite in different samples (milk, water, plasma and urine) in a straightforward way and with small error (1-6%). The sensitivity of the biosensor towards nitrite reduction under optimized conditions was 0.55 A M-1 cm(-2) with a linear response range 0.7-370 mu M. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

Free