TY - JOUR
T1 - A quasi-reagentless point-of-care test for nitrite and unaffected by oxygen and cyanide
AU - Monteiro, Tiago
AU - Gomes, Sara
AU - Jubete, Elena
AU - Añorga, Larraitz
AU - Silveira, Célia M.
AU - Almeida, Maria Gabriela
N1 - info:eu-repo/grantAgreement/FCT/5876/147258/PT#
info:eu-repo/grantAgreement/FCT/SFRH/SFRH%2FBPD%2F79566%2F2011/PT#
This work was supported by the Applied Molecular Biosciences Unit-UCIBIO which is financed by national funds from FCT/MCTES (UID/Multi/04378/2013) and co-financed by the ERDF under the PT2020 Partnership Agreement (POCI-01-0145-FEDER-007728). C.M.S. and T.M. thank the financial support from Fundacao para a Ciencia e Tecnologia (Fellowships SFRH/BPD/79566/2011 and PD/BD/109687/2015).
PY - 2019/12/1
Y1 - 2019/12/1
N2 -
The ubiquitous nitrite is a major analyte in the management of human health and environmental risks. The current analytical methods are complex techniques that do not fulfil the need for simple, robust and low-cost tools for on-site monitoring. Electrochemical reductase-based biosensors are presented as a powerful alternative, due to their good analytical performance and miniaturization potential. However, their real-world application is limited by the need of anoxic working conditions, and the standard oxygen removal strategies are incompatible with point-of-care measurements. Instead, a bienzymatic oxygen scavenger system comprising glucose oxidase and catalase can be used to promote anoxic conditions in aired environments. Herein, carbon screen-printed electrodes were modified with cytochrome c nitrite reductase together with glucose oxidase and catalase, so that nitrite cathodic detection could be performed by cyclic voltammetry under ambient air. The resulting biosensor displayed good linear response to the analyte (2–200 µM, sensitivity of 326 ± 5 mA M
−1
cm
−2
at −0.8 V; 0.8–150 µM, sensitivity of 511 ± 11 mA M
−1
cm
−2
at −0.5 V), while being free from oxygen interference and stable up to 1 month. Furthermore, the biosensor’s catalytic response was unaffected by the presence of cyanide, a well-known inhibitor of heme-enzymes.
AB -
The ubiquitous nitrite is a major analyte in the management of human health and environmental risks. The current analytical methods are complex techniques that do not fulfil the need for simple, robust and low-cost tools for on-site monitoring. Electrochemical reductase-based biosensors are presented as a powerful alternative, due to their good analytical performance and miniaturization potential. However, their real-world application is limited by the need of anoxic working conditions, and the standard oxygen removal strategies are incompatible with point-of-care measurements. Instead, a bienzymatic oxygen scavenger system comprising glucose oxidase and catalase can be used to promote anoxic conditions in aired environments. Herein, carbon screen-printed electrodes were modified with cytochrome c nitrite reductase together with glucose oxidase and catalase, so that nitrite cathodic detection could be performed by cyclic voltammetry under ambient air. The resulting biosensor displayed good linear response to the analyte (2–200 µM, sensitivity of 326 ± 5 mA M
−1
cm
−2
at −0.8 V; 0.8–150 µM, sensitivity of 511 ± 11 mA M
−1
cm
−2
at −0.5 V), while being free from oxygen interference and stable up to 1 month. Furthermore, the biosensor’s catalytic response was unaffected by the presence of cyanide, a well-known inhibitor of heme-enzymes.
UR - http://www.scopus.com/inward/record.url?scp=85062010407&partnerID=8YFLogxK
U2 - 10.1038/s41598-019-39209-y
DO - 10.1038/s41598-019-39209-y
M3 - Article
C2 - 30796298
AN - SCOPUS:85062010407
SN - 2045-2322
VL - 9
JO - Scientific Reports
JF - Scientific Reports
IS - 1
M1 - 2622
ER -