Amperometric Glucose Biosensor Electrode Modified with Carbon Nanotubes

Abstract

The construction of biosensors based on nanostructures is an attractive challenge, mainly due to the properties of these materials. New strategies involved in the design of biosensors include nanoparticles, nanowires and carbon nanotubes; which is expected to impact on clinic diagnosis, environmental and food analysis. Within the enzyme biosensors, glucose biosensors are further development, mainly due to the impact of diabetes on society.In this paper, we propose a platform for the immobilization of multi-walled carbon nanotubes (CNT), using nafion and polyethylenimine as dispersants and glucose oxidase, allowing a significant improvement in the quantification of glucose.

Enzyme co-immobilization: Always the biocatalyst designers' choice…or not?

“…For example, it has been recently published that immobilized ficin utilized in milk clotting has optimal activity when used at maximum loading, while poorly loaded biocatalysts were unable to produce milk coagulation (Siar et al, 2020). This competition in the loading of one enzyme with the loading of the other coimmobilized enzymes may be solved if using multilayer enzyme biocatalysts, where one enzyme is immobilized on an enzyme layer previously immobilized on the support (Deng et al, 2010;Forrest et al, 2005Forrest et al, , 2007Güleç et al, 2010;Gutiérrez et al, 2011;Ondul et al, 2012;Virgen-Ortíz et al, 2017a;Wong et al, 2013) (Figure 9). Using non-porous supports, there are no limits to the number of enzyme layers (that way, many different enzymes may be co-immobilized using this strategy) (Figure 9).…”

“…Furthermore, if one enzyme activity decreases much more than other enzyme activity during the immobilization, it is not possible to add more of this enzyme, as the researcher only has the enzyme cocktail, producing a biased or non-compensated combi-biocatalyst. (Deng et al, 2010;Forrest et al, 2005Forrest et al, , 2007Güleç et al, 2010;Gutiérrez et al, 2011;Ondul et al, 2012;Virgen-Ortíz et al, 2017a;Wong et al, 2013). Even with the enlargement of the operational window of use of immobilized enzymes when stability is increased, (Amaral-Fonseca et al, 2020;Dal Magro et al, 2020, 2019c it is very likely that the ratio between the different enzymes may be only valid under a specific condition and a specific reaction, also reducing the interest of the direct immobilization of these enzyme cocktails (Chen et al, 2017;Dutta and Wu, 2014).…”

“…The co-immobilized biocatalysts, taking into consideration the previous problems, will require a careful design of the ratio between the enzymes involved to maximize the overall biocatalyst activities (Deng et al, 2010;Forrest et al, 2005Forrest et al, , 2007Güleç et al, 2010;Gutiérrez et al, 2011;Ondul et al, 2012;Virgen-Ortíz et al, 2017a;Wong et al, 2013). The use of too much of one enzyme means the use of too few of another of the enzymes, and that way the advantages of the co-immobilizate will decrease.…”

Polyethylenimine: a very useful ionic polymer in the design of immobilized enzyme biocatalysts

“…The immobilization of multi-walled carbon nanotubes using nafion and polyethylenimine as dispersants and glucose oxidase as enzyme was utilized to improve the determination of glucose. 215 Selfpolymerization of dopamine on the surface of CaCO 3 particles was used to form polydopamine and used as an adhesive layer to bind PEI through Michael addition reaction or Schiff base reaction. Then, titania was generated and deposited on the surface of the PEI nanoparticles via bioinspired mineralization process initiated by the free amine groups of PEI.…”

Electrochemical Sensor for Hydrogen Peroxide Based on Prussian Blue Electrochemically Deposited at the TiO2-ZrO2–Doped Carbon Nanotube Glassy Carbon-Modified Electrode

“…The monitoring of low levels of H 2 O 2 is of great importance for modern medicine, environmental control, and various branches of industry ( Gutiérrez et al, 2011 ; Lv et al, 2020 ; Shu and Tang, 2020 ; Wang et al, 2020 ; Zhang et al, 2020 ; Hou et al, 2021 ; Xu et al, 2021 ). In particular, in biological applications, for example, there is the presence of H 2 O 2 in the human body that is converted into OH radicals with high reactivity; an overproduction of OH and O 2 at cell openings promote cell damage and tissue malfunctioning ( Rhee et al, 2010 ; Grisham, 2013 ).…”