| 1. |
- Antiochia, Riccarda, et al.
(författare)
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Composite Material Based on Macroporous Polyaniline and Osmium Redox Complex for Biosensor Development
- 2014
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Ingår i: Electroanalysis. - : Wiley. - 1040-0397. ; 26:7, s. 1623-1630
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Tidskriftsartikel (refereegranskat)abstract
- Here the feasibility of layers based on the conducting polymer polyaniline (PANI) as component of glucose biosensors using glucose oxidase (GOx) as enzyme and [Os(bpy)(2)(4-aminomethylpyridine)Cl]PF6 (OsCmplx) as electrochemical mediator, is evaluated. Particularly, PANI was employed to obtain a nanostructured macroporous material (m-PANI) around polystyrene nanoparticles taken as template and the mediator was co-immobilized during the polymerizing procedure. The GOx biosensor based on OsCmplx modified m-PANI provides a linear response to glucose concentration in the range 5 up to 65 mM with a sensitivity of 3.54 mu A/mM/cm(2) (on a projected geometric area=0.07 cm(2)), an LOD of 0.8 mM and a good precision (%RSD <= 7, n=5); the biosensor is stable showing a decrease of 10% to the value of the sensitivity after 15 days of use and of about 50% after 40 days.
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| 2. |
- 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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| 3. |
- 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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| 4. |
- Bollella, Paolo, et al.
(författare)
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Improved DET communication between cellobiose dehydrogenase and a gold electrode modified with a rigid self-assembled monolayer and green metal nanoparticles : The role of an ordered nanostructuration
- 2017
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Ingår i: Biosensors and Bioelectronics. - : Elsevier BV. - 0956-5663. ; 88, s. 196-203
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Tidskriftsartikel (refereegranskat)abstract
- Efficient direct electron transfer (DET) between cellobiose dehydrogenase from Corynascus thermophilus (CtCDH) and a novel gold electrode platform, obtained by covalent linking of green AuNPs and AgNPs modified with a dithiol self-assembled monolayer, consisting of biphenyl-4,4′-dithiol (BPDT), was presented. The green AuNPs and AgNPs were synthesized using quercetin as reducing agent at room temperature. TEM experiments showed that the AuNPs and AgNPs were circular in shape with an average diameter of 5 and 8 nm, respectively. Cyclic voltammetry of CtCDH immobilized onto the AuNPs/BPDT/AuE and the AgNPs/BPDT/AuE electrode platforms were carried out and compared with naked AuE, BPDT/AuE, AuNPs/AuE, and AgNPs/AuE. A pair of well-defined redox waves in neutral pH solution due to efficient DET of CtCDH was present with both MNPs/BPDT/AuE platforms. No DET communication was found with platforms without MNPs linked to BPDT. The apparent heterogeneous electron transfer rate constants (kS) of CtCDH were calculated to be 21.5±0.8 s−1 and 10.3±0.7 s−1, for the AuNPs/BPDT/AuE and the AgNPs/BPDT/AuE platforms, respectively. The modified electrodes were successively used to develop an eco-friendly biosensor for lactose detection. The CtCDH/AuNPs/BPDT/AuE based biosensor showed the best analytical performances with an excellent stability, a detection limit of 3 µM, a linear range between 5 and 400 µM and a sensitivity of 27.5±2.5 µA cm−2 mM−1. Such performances were favorably compared with other lactose biosensors reported in literature. The biosensor was successively tested to quantify lactose content in real milk and cream samples. No significant interference present in the sample matrices was observed.
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| 5. |
- Ciogli, Leonardo, et al.
(författare)
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Highly Sensitive Hydrogen Peroxide Biosensor Based on Tobacco Peroxidase Immobilized on p-Phenylenediamine Diazonium Cation Grafted Carbon Nanotubes : Preventing Fenton-like Inactivation at Negative Potential
- 2021
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Ingår i: ChemElectroChem. - : Wiley. - 2196-0216. ; 8:13, s. 2495-2504
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Tidskriftsartikel (refereegranskat)abstract
- Herein, we present a novel electrode platform for H2O2 detection based on the immobilization of recombinant Tobacco Peroxidase (r-TOP) onto graphite electrodes (G) modified with p-phenylenediamine (p-PD) diazonium cation grafted multi-walled carbon nanotubes (MWCNTs). The employment of both p-phenylenediamine moieties and covalent cross-linking by using glutaraldehyde allowed us to enhance the sensitivity, stability, and selectivity toward H2O2 detection, as well as preventing enzyme inactivation due to the electro-Fenton reaction. This reaction continuously produces hydroxyl radicals, whose high and unselective reactivity is likely to reduce drastically the operating life of the biosensor. The protection against the electro-Fenton reaction is mainly ascribed to a beneficial enzyme immobilization leading to a correct orientation achieved through cross-linking the enzyme in combination with interaction between the uncoupled -NH2 groups (mainly uncharged at pH 7, considering a pKa of 4.6) available on the electrode surface and the enzyme. In particular, the electrode based on the r-TOP/p-PD/MWCNTs/G platform showed a lower limit of detection of 1.8 μM H2O2, an extended linear range between 6 and 900 μM H2O2, as well as a significant increase in sensitivity (63.1±0.1 μA mM−1 cm−2) compared with previous work based on TOP. Finally, the r-TOP/p-PD/MWCNTs/G electrode was tested in several H2O2 spiked food samples as a screening analytical method for the detection of H2O2.
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| 6. |
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| 7. |
- Sanzò, Gabriella, et al.
(författare)
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A bimetallic nanocoral Au decorated with Pt nanoflowers (bio)sensor for H2O2 detection at low potential
- 2017
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Ingår i: Methods. - : Elsevier BV. - 1046-2023. ; 129, s. 89-95
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we have developed for the first time a method to make novel gold and platinum hybrid bimetallic nanostructures differing in shape and size. Au-Pt nanostructures were prepared by electrodeposition in two simple steps. The first step consists of the electrodeposition of nanocoral Au onto a gold substrate using hydrogen as a dynamic template in an ammonium chloride solution. After that, the Pt nanostructures were deposited onto the nanocoral Au organized in pores. Using Pt (II) and Pt (IV), we realized nanocoral Au decorated with Pt nanospheres and nanocoral Au decorated with Pt nanoflowers, respectively. The bimetallic nanostructures showed better capability to electrochemically oxidize hydrogen peroxide compared with nanocoral Au. Moreover, Au-Pt nanostructures were able to lower the potential of detection and a higher performance was obtained at a low applied potential. Then, glucose oxidase was immobilized onto the bimetallic Au-Pt nanostructure using cross-linking with glutaraldehyde. The biosensor was characterized by chronoamperometry at +0.15V vs. Ag pseudo-reference electrode (PRE) and showed good analytical performances with a linear range from 0.01 to 2.00mM and a sensitivity of 33.66μA/mMcm2. The good value of Km app (2.28mM) demonstrates that the hybrid nanostructure is a favorable environment for the enzyme. Moreover, the low working potential can minimize the interference from ascorbic acid and uric acid as well as reducing power consumption to effect sensing. The simple procedure to realize this nanostructure and to immobilize enzymes, as well as the analytical performances of the resulting devices, encourage the use of this technology for the development of biosensors for clinical analysis.
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