scholarly journals Improved Solid-Contact Nitrate Ion Selective Electrodes Based on Multi-Walled Carbon Nanotubes (MWCNTs) as an Ion-to-Electron Transducer

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3891 ◽  
Author(s):  
Hassan ◽  
Eldin ◽  
Amr ◽  
Al-Omar ◽  
Kamel ◽  
...  

Possible improvement of the performance characteristics, reliability and selectivity of solid-contact nitrate ion-selective electrodes (ISE) (SC/NO3−-ISE) is attained by the application of a nitron-nitrate (Nit+/NO3−) ion association complex and inserting multi-walled carbon nanotubes (MWCNTs) as an ion-to-electron transducer between the ion sensing membrane (ISM) and the electronic conductor glassy carbon (GC) substrate. The potentiometric performance of the proposed electrode revealed a Nernstian slope −55.1 ± 2.1 (r² = 0.997) mV/decade in the range from 8.0 × 10−8–1 × 10−2 M with a detection limit of 2.8 × 10−8 (1.7 ng/mL). Selectivity, repeatability and reproducibility of the proposed sensors were considerably improved as compared to the coated disc electrode (GC/NO3−-ISE) without insertion of a MWCNT layer. Short-term potential stability and capacitance of the proposed sensors were tested using a current-reversal chronopotentiometric technique. The potential drift in presence of a MWCNT layer decreased from 167 μVs−1 (i.e., in absence of MWCNTs) to 16.6 μVs−1. In addition, the capacitance was enhanced from 5.99 μF (in absence of MWCNTs) to 60.3 μF (in the presence of MWCNTs). The presented electrodes were successfully applied for nitrate determination in real samples with good accuracy.

2011 ◽  
Vol 23 (6) ◽  
pp. 1352-1358 ◽  
Author(s):  
Zekra Mousavi ◽  
Agnieszka Teter ◽  
Andrzej Lewenstam ◽  
Magdalena Maj-Zurawska ◽  
Ari Ivaska ◽  
...  

The Analyst ◽  
2009 ◽  
Vol 134 (9) ◽  
pp. 1905 ◽  
Author(s):  
Enrique J. Parra ◽  
Gastón A. Crespo ◽  
Jordi Riu ◽  
Aurora Ruiz ◽  
F. Xavier Rius

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2550 ◽  
Author(s):  
Yueling Liu ◽  
Yingying Gao ◽  
Rui Yan ◽  
Haobo Huang ◽  
Ping Wang

Potentiometric plasticizer-free solid-contact Pb2+-selective electrodes based on copolymer methyl methacrylate-n-butyl acrylate (MMA-BA) as membrane matrix and multi-walled carbon nanotubes (MWCNTs) as intermediate ion-to-electron transducing layer have been developed. The disposable electrodes were prepared by drop-casting the copolymer membrane onto a layer of MWCNTs, which deposited on golden disk electrodes. The obtained electrodes exhibited a sub-ppb level detection limit of 10−10 mol·L−1. The proposed electrodes demonstrated a Nernstian slope of 29.1 ± 0.5 mV/decade in the linear range from 2.0 × 10−10 to 1.5 × 10−3 mol·L−1. No interference from gases (O2 and CO2) or water films was observed. The electrochemical impedance spectroscopy of the fabricated electrodes was compared to that of plasticizer-free Pb2+-selective electrodes without MWCNTs as intermediated layers. The plasticizer-free MWCNTs-based Pb2+-selective electrodes can provide a promising platform for Pb(II) detection in environmental and clinical application.


2009 ◽  
Vol 395 (7) ◽  
pp. 2371-2376 ◽  
Author(s):  
Gastón A. Crespo ◽  
Derese Gugsa ◽  
Santiago Macho ◽  
F. Xavier Rius

Acta Naturae ◽  
2011 ◽  
Vol 3 (1) ◽  
pp. 99-106 ◽  
Author(s):  
E A Smirnova ◽  
A A Gusev ◽  
O N Zaitseva ◽  
E M Lazareva ◽  
G E Onishchenko ◽  
...  

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