Amperometric nitrate biosensor based on Carbon nanotube/Polypyrrole/Nitrate reductase biofilm electrode

Techniques in Advancing the Capabilities of Various Nitrate Detection Methods: A Review

“…However, the conventional electrochemical cell is too massive to be a portable and durable device. Research into electrochemical systems for nitrate detection has followed several avenues [25][26][27]. This is due to the demand for portable devices for continuous monitoring of nitrate concentration in aqueous solutions.…”

“…Table 5 summarises the main advantages and disadvantages of electrochemical systems. [29,30,56,66,68,72] * Less power consumption during operation [28,30] * Simple operation for direct determination of nitrate [29,30,68] *High selectivity towards targeted ions [30,56] *Fast response/feedback system [66,67] *Suitable for in situ/on line analyses [30,66] *Viable approach for portable application as relatively simple [30,56] *Low-cost system [56,68] *Small and compact system [29,30] *Surface cumulative passivation effect [28] *Complicated programmed potential protocol for renewal of microelectrode surface/electrode reactivation [28] *Extensive procedure for reagent preparation [27] *Measurement result is influenced by other contamination in analyte solution/samples [26] *Tedious reagent preparation procedure [27] *Sensitive materials such as dope polypyrrole need to be stored in the dark during polymerisation [26,29] *Sensitive materials such as dope polypyrrole are expensive [29,30] *Sensitive materials such as nitrate reductase enzymes are too sophisticated to be field-deployable [29,30] *Interference of other ions in water such as chloride, sulphate and phosphate [26] *Requirement of different types of material for the electrode in the system such as working, counter and reference electrode [27,…”

“…CNTs can donate and accept electrons in a wide range of potentials, and could therefore be used as mediators in biosensor systems. As a result, [27] investigated the performance of carbon nanotube/Polypyrrole/Nitrate reductase biofilm electrodes for nitrate detection. Table 8 summarises the different types of biological material, detection systems, LOD and applications of biosensor systems for nitrate ion detection.…”

Recent advances in biosensors based on enzyme inhibition

“…Chitosan, Nafion and conducting polymeric films were usually employed as support for fixation of nanomaterials and enzymes (Oliveira et al, 2014;Moyo et al, 2014b;Can et al, 2012;Gong et al, 2009. To this regards, other materials were also employed, like Cu-Mg-Al calcined layered double hydroxide (Zhai et al, 2014), Mg/Al layered double hydroxides and the polyelectrolyte polydiallyldimethylammonium chloride .…”

Electrochemical detection of nitrate in PM2.5 with a copper-modified carbon fiber micro-disk electrode

“…It is characterized by low sensitivity and irreproducibility and associated with surface passivation effects [29]. Therefore, a large number of strategies have been developed to modify electrode with some sensitive materials, such as copper [30,31], silver [32,33], cadmium [34,35], lead [36,37], palladium [38,39], polypyrrol materials [40], boron-doped diamond electrodes [41,42], and more recently, biocatalysts [43,44]. Among these materials, metallic copper is the most popular one because of its great advantages of low cost, good electrocatalysis and easy eletrodeposition [45][46][47].…”