Improving the retention and reusability of Alpha-amylase by immobilization in nanoporous polyacrylamide-graphene oxide nanocomposites

Mulko, Lucinda; Pereyra, Jesica Yanina del Carmen; Rivarola, Claudia R.; Barbero, C.; Acevedo, Diego F.

doi:10.1016/j.ijbiomac.2018.09.078

Cited by 36 publications

(18 citation statements)

References 47 publications

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“…Natural graphite powder (Aldrich) was oxidized using the modified Hummers method [37]. The GO synthesis depicted has been extensively employed, as well as the GO produced has been exhaustively characterized by our research group [18,35,38]. Briefly, graphite powder (2 g) was added to concentrated H 2 SO 4 (200 mL) immersed in an ice bath.…”

Section: Synthesismentioning

confidence: 99%

“…The FTIR spectra of the PAAm and NanoC are shown in Figure 1a. The GO synthesis depicted in the NanoC preparation has been extensively employed as well as exhaustively characterized in previous work of our research group [18,35,38]. Following the synthetic procedure reported, it is possible to obtain GO, a very oxidized material [40], with a ID/IG ratio (measured by Raman spectroscopy) of ca.…”

Section: Synthesis and Characterizationmentioning

confidence: 99%

“…This is in contrast with modified electrodes where complex data analysis is required [34], since the diffusion is constrained by the finite thickness of the films.Consider the above mentioned, the incorporation of GO into a soft matrix based on crosslinked acrylamides to obtain a nanocomposite (NanoC) that works as an active material is shown. NanoC offers the following useful advantage: (i) the application to electrochemically determinate DA is straightforward, since it is not necessary to modify the glassy carbon electrode; (ii) the manipulation is easy, because NanoC is a monolithic piece separated from an electrode that can be synthesized in bulk; (iii) NanoC can be independently characterized by: ultraviolet-visible (UV-vis) and FTIR spectroscopies, scanning electron microscopy (SEM), mechanical assays and others [18,35]; and (iv) since the solid NanoC acts as electrolyte, the sampling of analytes from different environments could be separated from the electrochemical detection, allowing the building of portable devices.In this research work, NanoC was used as a platform to preload and detect simultaneously DA and AA, using a bare glassy carbon without further treatment, by employing electrochemical technique. The nanocomposite interacts selectively with the molecules under study choosing a suitable pH.…”

mentioning

confidence: 99%

“…Consider the above mentioned, the incorporation of GO into a soft matrix based on crosslinked acrylamides to obtain a nanocomposite (NanoC) that works as an active material is shown. NanoC offers the following useful advantage: (i) the application to electrochemically determinate DA is straightforward, since it is not necessary to modify the glassy carbon electrode; (ii) the manipulation is easy, because NanoC is a monolithic piece separated from an electrode that can be synthesized in bulk; (iii) NanoC can be independently characterized by: ultraviolet-visible (UV-vis) and FTIR spectroscopies, scanning electron microscopy (SEM), mechanical assays and others [18,35]; and (iv) since the solid NanoC acts as electrolyte, the sampling of analytes from different environments could be separated from the electrochemical detection, allowing the building of portable devices.…”

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confidence: 99%

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Hydrogel-Graphene Oxide Nanocomposites as Electrochemical Platform to Simultaneously Determine Dopamine in Presence of Ascorbic Acid Using an Unmodified Glassy Carbon Electrode

et al. 2018

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The detection of dopamine, an important neurotransmitter in the central nervous system, is relevant because low levels of dopamine can cause brain disorders. Here, a novel electrochemical platform made of a hydrogel–graphene oxide nanocomposite was employed to electrochemically determine simultaneously dopamine (DA) and ascorbic acid (AA). Unlike previous work, where the base electrode is modified, the active material (graphene oxide, GO) was dispersed in the hydrogel matrix, making an active nanocomposite where the electrochemical detection occurs. The GO, hydrogel and nanocomposite synthesis is described. Dynamic Light Scattering, UV-visible and FTIR spectroscopies showed that the synthesized GO nanoparticles present 480 nm of diagonal size and a few sheets in height. Moreover, the polymer swelling, the adsorption capacity and the release kinetic of DA and AA were evaluated. The nanocomposite showed lower swelling capacity, higher DA partition coefficient and faster DA release rate than in the hydrogel. The electrochemical measurement proved that both materials can be employed to determine DA and AA. Additionally, the nanocomposite platform allowed the simultaneous determination of both molecules showing two well separated anodic peaks. This result demonstrates the importance of the incorporation of the nanomaterial inside of the hydrogel and proves that the nanocomposite can be used as a platform in an electrochemical device to determinate DA using an unmodified glassy carbon electrode.

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Section: Synthesismentioning

confidence: 99%

Section: Synthesis and Characterizationmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Hydrogel-Graphene Oxide Nanocomposites as Electrochemical Platform to Simultaneously Determine Dopamine in Presence of Ascorbic Acid Using an Unmodified Glassy Carbon Electrode

et al. 2018

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“…Among various nanoparticles, graphene oxide (GO) is a chemically derivatized graphene sheet carrying abundant surface oxygen‐containing groups including hydroxyl, carboxylic group, and epoxy . Those surface functional groups can provide a number of reaction sites for linking external species, such as small molecules , polymers , biomacromolecules , and nanoparticles without additional surface modification or using any cross‐linking reagents. Because of their unique surface functionality and structural characteristics, GO sheets have been used as a solid substrate for enzyme immobilization through noncovalent adsorption and covalent binding in recent years .…”

Section: Introductionmentioning

confidence: 99%

Capillary electrophoresis‐integrated immobilized enzyme microreactor with graphene oxide as support: Immobilization of negatively charged L‐lactate dehydrogenase via hydrophobic interactions

Yin

Cui

et al. 2019

Electrophoresis

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We report the first application of hydrophobic interaction between graphene oxide (GO) and negatively charged enzymes to fabricate CE-integrated immobilized enzyme microreactors (IMERs) by a simple and reliable immobilization procedure based on layer by layer assembly. L-lactate dehydrogenase (L-LDH), which is negatively charged during the enzymatic reaction, is selected as the model enzyme. Various spectroscopic techniques, including SEM, FTIR, and UV-vis are used to characterize the fabricated CE-IMERs, demonstrating the successful immobilization of enzymes on the negatively charged GO layer in the capillary surface. The IMER exhibits excellent repeatability with RSDs of interday and batch-to-batch less than 3.49 and 6.37%, respectively, and the activity of immobilized enzymes remains about 90% after five-day usage. The measured K m values of pyruvate and NADH of the immobilized L-LDH are in good agreement with those obtained by free enzymes. The results demonstrate that the hydrophobic interactions and/or π-π stacking is significant between the GO backbone and the aromatic residues of L-LDH and favorable to fabrication of CE-integrated IMERs. Finally, the method is successfully applied to the determination of pyruvate in beer samples.Abbreviations: GO, graphene oxide; IMER, immobilized enzyme microreactor; L-LDH, L-lactate dehydrogenase; NAD + , β-Nicotinamide adenine dinucleotide hydrate; NADH, β-Nicotinamide adenine dinucleotide, reduced disodium salt hydrate; PDDA, poly (diallyldimethylammonium chloride); UV-vis, ultraviolet-visible * These authors contributed equally in this work.Color online: See the article online to view Figs. 1-3 and 5 in color.

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Immobilized Enzymes for Bioconversion of Waste to Wealth

Balan¹,

Murthy²,

Kadeppagari³

2022

Biotechnology for Zero Waste

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Improving the retention and reusability of Alpha-amylase by immobilization in nanoporous polyacrylamide-graphene oxide nanocomposites

Cited by 36 publications

References 47 publications

Hydrogel-Graphene Oxide Nanocomposites as Electrochemical Platform to Simultaneously Determine Dopamine in Presence of Ascorbic Acid Using an Unmodified Glassy Carbon Electrode

Hydrogel-Graphene Oxide Nanocomposites as Electrochemical Platform to Simultaneously Determine Dopamine in Presence of Ascorbic Acid Using an Unmodified Glassy Carbon Electrode

Capillary electrophoresis‐integrated immobilized enzyme microreactor with graphene oxide as support: Immobilization of negatively charged L‐lactate dehydrogenase via hydrophobic interactions

Immobilized Enzymes for Bioconversion of Waste to Wealth

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