| 1. |
- Bollella, Paolo, et al.
(författare)
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The influence of the shape of Au nanoparticles on the catalytic current of fructose dehydrogenase
- 2019
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 411:29, s. 7645-7657
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Tidskriftsartikel (refereegranskat)abstract
- Graphite electrodes were modified with triangular (AuNTrs) or spherical (AuNPs) nanoparticles and further modified with fructose dehydrogenase (FDH). The present study reports the effect of the shape of these nanoparticles (NPs) on the catalytic current of immobilized FDH pointing out the different contributions on the mass transfer–limited and kinetically limited currents. The influence of the shape of the NPs on the mass transfer–limited and the kinetically limited current has been proved by using two different methods: a rotating disk electrode (RDE) and an electrode mounted in a wall jet flow-through electrochemical cell attached to a flow system. The advantages of using the wall jet flow system compared with the RDE system for kinetic investigations are as follows: no need to account for substrate consumption, especially in the case of desorption of enzyme, and studies of product-inhibited enzymes. The comparison reveals that virtually identical results can be obtained using either of the two techniques. The heterogeneous electron transfer (ET) rate constants (kS) were found to be 3.8 ± 0.3 s−1 and 0.9 ± 0.1 s−1, for triangular and spherical NPs, respectively. The improvement observed for the electrode modified with AuNTrs suggests a more effective enzyme-NP interaction, which can allocate a higher number of enzyme molecules on the electrode surface.
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| 2. |
- Antiochia, Riccarda, et al.
(författare)
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Graphene and 2D-Like Nanomaterials : Different Biofunctionalization Pathways for Electrochemical Biosensor Development
- 2017
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Ingår i: Graphene Bioelectronics. - 9780128133507 - 9780128133491 ; , s. 1-35
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Bokkapitel (refereegranskat)abstract
- In the last decades, nanotechnology has played a key role in the electrochemical biosensor development based on the mediated and direct electrochemical communication between the biorecognition elements and the electrode surface. In particular, graphene and 2D-like nanomaterials (e.g., boron nitride nanosheets, graphitic carbon nitride (g-C3N4) nanosheets, and various transition metal dichalcogenides) have attracted an increasing interest due to their peculiar properties such as high specific surface area and the ease of biofunctionalization. Moreover, in the last few years, the successful integration of graphene and 2D-like nanomaterials with other nanomaterials such as metal nanoparticles, metal oxides, or quantum dots has dramatically increased the opportunities to develop novel electrochemical biosensors with highly enhanced performances, mainly due to the synergistic effects.In this chapter, we would like to give the state of art of graphene and 2D-like nanomaterials employment for electrochemical biosensors development, by critically discussing the advantages and drawbacks. Successively, the discussion should be separately addressed to three different cases: (1) redox enzyme immobilization, (2) antibody immobilization, and (3) DNA/aptamer immobilization. Finally, we should critically define for which cases graphene and 2D-like nanomaterials are the most suitable electrochemical platform, within some conclusion remarks and future perspectives of both kinds of nanomaterials.
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| 3. |
- Bollella, Paolo, et al.
(författare)
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A Glucose/Oxygen Enzymatic Fuel Cell based on Gold Nanoparticles modified Graphene Screen-Printed Electrode. Proof-of-Concept in Human Saliva
- 2018
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Ingår i: Sensors and Actuators B: Chemical. - : Elsevier BV. - 0925-4005. ; 256, s. 921-930
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a new direct electron transfer based-miniaturized glucose/oxygen enzymatic fuel cell (EFC) whose operating ability has been tested in real saliva samples. The bioanode and biocathode are a graphene working electrode and a graphite counter electrode localized on the same screen printed electrode (SPE) modified with poly(vinyl alcohol) N-methyl-4(4'-formylstyryl)pyridinium methosulfate acetal (PVA-SbQ)/cellobiose dehydrogenase from Corynascus Thermophilus (CtCDH) C291Y/AuNPs and with Trametes Hirsuta laccase (ThLac)/AuNPs, respectively.In order to optimize the bioanode, several CDH immobilization procedures were adopted, such as drop-casting, use of Nafion membrane or PVA-SbQ photopolymer. The photopolymer showed the best performance in terms of stability and reliability. As biocathode a partially optimized laccase electrode was employed with the variant that the used nanomaterials allowed to reduce the overpotential of O2/H2O redox reaction catalyzed by Trametes Hirsuta Laccase (ThLac), drop-casted onto the gold nanoparticles (AuNPs) modified SPE.The performances of bioanode and biocathode were tested separately, initially immobilizing the two enzymes onto separated graphene SPEs. An efficient direct electron transfer was achieved for both elements, obtaining an apparent heterogeneous electron transfer rate constant (ks ) of 0.99±0.05s-1 for CtCDH C291Y and 5.60±0.05s-1 for ThLac. Both electrodes were then assembled in a two compartment EFC obtaining a maximal power output of 5.16±0.15μWcm-2 at a cell voltage of 0.58V and an open circuit voltage (OCV) of 0.74V. Successively, the bioanode and biocathode were assembled in a non-compartmentalized EFC and a remarkable 50% decrease of the maximum power output at the value of 2.15±0.12μWcm-2 at cell voltage of 0.48V and an OCV of 0.62V at pH 6.5 was registered. In order to reduce the cell dimensions in view of its possible integration in biomedical devices, the bioanode and biocaythode were realized by immobilization of both enzymes onto the same SPE. The so miniaturized EFC delivered a maximal power output of 1.57±0.07μWcm2 and 1.10±0.12μWcm-2 with an OCV of 0.58V and 0.41V in a 100μM glucose solution and in human saliva, respectively.
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| 4. |
- Bollella, Paolo, et al.
(författare)
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A third generation glucose biosensor based on cellobiose dehydrogenase immobilized on a glassy carbon electrode decorated with electrodeposited gold nanoparticles : Characterization and application in human saliva
- 2017
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Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 17:8
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Tidskriftsartikel (refereegranskat)abstract
- Efficient direct electron transfer (DET) between a cellobiose dehydrogenase mutant from Corynascus thermophilus (CtCDH C291Y) and a novel glassy carbon (GC)-modified electrode, obtained by direct electrodeposition of gold nanoparticles (AuNPs) was realized. The electrode was further modified with a mixed self-assembled monolayer of 4-aminothiophenol (4-APh) and 4-mercaptobenzoic acid (4-MBA), by using glutaraldehyde (GA) as cross-linking agent. The CtCDH C291Y/GA/4-APh,4-MBA/AuNPs/GC platform showed an apparent heterogeneous electron transfer rate constant (ks) of 19.4 ± 0.6 s−1, with an enhanced theoretical and real enzyme surface coverage (Γtheor and Γreal) of 5287 ± 152 pmol cm−2 and 27 ± 2 pmol cm−2, respectively. The modified electrode was successively used as glucose biosensor exhibiting a detection limit of 6.2 μM, an extended linear range from 0.02 to 30 mM, a sensitivity of 3.1 ± 0.1 μA mM−1 cm−2 (R2 = 0.995), excellent stability and good selectivity. These performances compared favourably with other glucose biosensors reported in the literature. Finally, the biosensor was tested to quantify the glucose content in human saliva samples with successful results in terms of both recovery and correlation with glucose blood levels, allowing further considerations on the development of non-invasive glucose monitoring devices.
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| 5. |
- Bollella, Paolo, et al.
(författare)
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Beyond graphene : Electrochemical sensors and biosensors for biomarkers detection
- 2017
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Ingår i: Biosensors and Bioelectronics. - : Elsevier BV. - 0956-5663. ; 89, s. 152-166
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Tidskriftsartikel (refereegranskat)abstract
- Graphene's success has stimulated great interest and research in the synthesis and characterization of graphene-like 2D materials, single and few-atom-thick layers of van der Waals materials, which show fascinating and technologically useful properties. This review presents an overview of recent electrochemical sensors and biosensors based on graphene and on graphene-like 2D materials for biomarkers detection. Initially, we will outline different electrochemical sensors and biosensors based on chemically derived graphene, including graphene oxide and reduced graphene oxide, properly functionalized for improved performances and we will discuss the various strategies to prepare graphene modified electrodes. Successively, we present electrochemical sensors and biosensors based on graphene-like 2D materials, such as boron nitride (BN), graphite-carbon nitride (g-C3N4), transition metal dichalcogenides (TMDs), transition metal oxides and graphane, outlining how the new modified 2D nanomaterials will improve the electrochemical performances. Finally, we will compare the results obtained with different sensors and biosensors for the detection of important biomarkers such as glucose, hydrogen peroxide and cancer biomarkers and highlight the advantages and disadvantages of the use of graphene and graphene-like 2D materials in different sensing platforms.
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| 6. |
- Bollella, Paolo, et al.
(författare)
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Cellobiose dehydrogenase : Insights on the nanostructuration of electrodes for improved development of biosensors and biofuel cells
- 2017
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Ingår i: Applied Materials Today. - : Elsevier BV. - 2352-9407. ; 9, s. 319-332
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Forskningsöversikt (refereegranskat)abstract
- Cellobiose dehydrogenase (CDH) is a versatile bioelectrocatalyst lately at focus due to its sugar oxidising properties in combination with its inherent ability for direct electron transfer communication with electrodes making it possible to be used in bioanodes in the enzymatic fuel cells (EFCs), self-powered biosensors, and biosupercapacitors. During the last 20 years, many new nanomaterials and hybrid nanocomposites have been developed and employed in combination with various oxidoreductases, such as CDH, to increase the overall performance of electrical devices (e.g. biosensors, EFCs etc.). It has also been shown that nanomaterials can be further chemically modified to facilitate electron transfer pathways between the biocomponent and electrodes. Both carbon and metal based nanomaterials and combinations thereof have been used together with CDH to improve the performance. In this review, we resume all the findings related to the influence of effective nanostructuration to improve the electron transfer communication with electrodes yielding higher sensitivity of biosensors or increasing the power output of EFC based on CDH from different sources.
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| 7. |
- Bollella, Paolo, et al.
(författare)
-
Direct electron transfer of dehydrogenases for development of 3rd generation biosensors and enzymatic fuel cells
- 2018
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Ingår i: Sensors (Switzerland). - : MDPI AG. - 1424-8220. ; 18:5
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Forskningsöversikt (refereegranskat)abstract
- Dehydrogenase based bioelectrocatalysis has been increasingly exploited in recent years in order to develop new bioelectrochemical devices, such as biosensors and biofuel cells, with improved performances. In some cases, dehydrogeases are able to directly exchange electrons with an appropriately designed electrode surface, without the need for an added redox mediator, allowing bioelectrocatalysis based on a direct electron transfer process. In this review we briefly describe the electron transfer mechanism of dehydrogenase enzymes and some of the characteristics required for bioelectrocatalysis reactions via a direct electron transfer mechanism. Special attention is given to cellobiose dehydrogenase and fructose dehydrogenase, which showed efficient direct electron transfer reactions. An overview of the most recent biosensors and biofuel cells based on the two dehydrogenases will be presented. The various strategies to prepare modified electrodes in order to improve the electron transfer properties of the device will be carefully investigated and all analytical parameters will be presented, discussed and compared.
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| 8. |
- Bollella, Paolo, et al.
(författare)
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Enhanced Direct Electron Transfer of Fructose Dehydrogenase Rationally Immobilized on a 2-Aminoanthracene Diazonium Cation Grafted Single-Walled Carbon Nanotube Based Electrode
- 2018
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Ingår i: ACS Catalysis. - : American Chemical Society (ACS). - 2155-5435. ; , s. 10279-10289
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, an efficient direct electron transfer (DET) reaction was achieved between fructose dehydrogenase (FDH) and a glassy-carbon electrode (GCE) upon which anthracene-modified single-walled carbon nanotubes were deposited. The SWCNTs were activated in situ with a diazonium salt synthesized through the reaction of 2-aminoanthracene with NaNO2 in acidic media (0.5 M HCl) for 5 min at 0 °C. After the in situ reaction, the 2-aminoanthracene diazonium salt was electrodeposited by running cyclic voltammograms from +1000 to -1000 mV. The anthracene-SWCNT-modified GCE was further incubated in an FDH solution, allowing enzyme adsorption. Cyclic voltammograms of the FDH-modified electrode revealed two couples of redox waves possibly ascribed to the heme c1 and heme c3 of the cytochrome domain. In the presence of 10 mM fructose two catalytic waves could clearly be seen and were correlated with two heme cs (heme c1 and c2), with a maximum current density of 485 ± 21 μA cm-2 at 0.4 V at a sweep rate of 10 mV s-1. In contrast, for the plain SWCNT-modified GCE only one catalytic wave and one couple of redox waves were observed. Adsorbing FDH directly onto a GCE showed no non-turnover electrochemistry of FDH, and in the presence of fructose only a slight catalytic effect could be seen. These differences can be explained by considering the hydrophobic pocket close to heme c1, heme c2, and heme c3 of the cytochrome domain at which the anthracenyl aromatic structure could interact through π-π interactions with the aromatic side chains of the amino acids present in the hydrophobic pocket of FDH.
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| 9. |
- Bollella, Paolo, et al.
(författare)
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Enzyme based amperometric biosensors
- 2018
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Ingår i: Current Opinion in Electrochemistry. - : Elsevier BV. - 2451-9103. ; 10, s. 157-173
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Forskningsöversikt (refereegranskat)abstract
- Current research on enzyme based electrochemical biosensors deals essentially with the same target analytes as was at focus in the early days of biosensor research, that is those within the clinical/medical, food/agriculture, and environmental fields [1•–13]. However, there has been substantial progress through the years and progress continues, as resumed in Figure 1A. One of the major differences is that (bio)electrochemists finally seem to start to understand what kind of molecules they deal with, that is with biological molecules and vice versa, biochemists, (micro)biologists start to become interested in (bio)electrochemistry. This is clearly shown for example in the recent very intense research on biofuel cells [14–26] and lately also on biosupercapacitors [27] that has absolutely had a great influence on current research on enzyme based biosensors and bioelectrochemistry as a whole.
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| 10. |
- Bollella, Paolo, et al.
(författare)
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Green Synthesis and Characterization of Gold and Silver Nanoparticles and their Application for Development of a Third Generation Lactose Biosensor
- 2017
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Ingår i: Electroanalysis. - : Wiley. - 1040-0397. ; 29:1, s. 77-86
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we report on a facile, cost effective and environmental friendly green synthesis method of gold and silver nanoparticles (NPs) by using quercetin as reducing agent. The obtained NPs were characterized by transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), dynamic light scattering (DLS) and UV-Vis spectroscopy and parameters such as pH, ionic strength and temperature, effectively affecting shape and size of NPs, have been carefully studied and optimized. The obtained results showed that the synthesized NPs were circular in shape with an average diameter of 5 and 8 nm for the AuNPs and the AgNPs, respectively. The “green” NPs, showing increased electroactive areas (AEA) and electronic transfer rate constants (k0), were successively used to fabricate a novel third generation lactose biosensor based on cellobiose dehydrogenase from Trametes villosa (TvCDH). The TvCDH/AuNPs based lactose biosensor revealed the best results showing very efficient DET and a detection limit for lactose of 3.5 mM, a large linear range from 10 to 300 mM, a high sensitivity (5.4 μA mM−1 cm−2) and long-term stability.
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