Third-generation biosensors based on TiO2 nanostructured films

Viticoli, M.; Curulli, Antonella; Cusmà, A.; Kačiulis, S.; Nunziante, S. Panice; Pandolfi, L.; Valentini, Federica; Padeletti, G.

doi:10.1016/j.msec.2005.09.080

Cited by 95 publications

(52 citation statements)

References 17 publications

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“…The shape of the single nanotubes 14 (with a diameter of about 50 nm) is still visible, evidencing that the entrapment of GOD is following the morphology of the substrate. A similar behaviour of the enzymes was observed 16 in the samples of GOD and HRP on TiO 2 nanostructured films. The mean size of the grains of the TiO 2 film surface was of ³30 nm, while after the GOD immobilization this size was of ³40 nm.…”

Section: Resultssupporting

confidence: 81%

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Immobilization of GOD and HRP enzymes on nanostructured substrates

Curulli

Cusmà

Kačiulis

et al. 2006

Surface & Interface Analysis

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The study of the entrapment of glucose oxidase (GOD) and horseradish peroxidase (HRP) enzymes on different solid-state substrates has been carried out. By using conventional methods, these enzymes have been immobilized on the following substrates: commercial Si wafers, thin films of nanostructured TiO 2 and gold nanotubes grown on polycarbonate membranes. Surface chemical composition and morphology of the samples have been investigated by means of X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Peak-fitting analysis of the main XPS signals permitted identification of the fingerprints of GOD and HRP enzymes and comparison of their entrapment on different substrates. The highest amount of attached enzymes was registered on the nanostructured TiO 2 films prepared by using the sol-gel technique. Moreover, the surface impurities, remaining on the samples after the immobilization of the phosphate buffer solution, were identified, and their removability by sample washing in deionized water was demonstrated.

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Section: Resultssupporting

confidence: 81%

“…The Si substrates were covered with the nanostructured TiO 2 film by the sol-gel technique, 16 using Ti 4 C isopropoxide as a starting precursor. Then, the GOD or HRP enzymes were immobilized on the TiO 2 surface.…”

Section: Methodsmentioning

confidence: 99%

Immobilization of GOD and HRP enzymes on nanostructured substrates

Curulli

Cusmà

Kačiulis

et al. 2006

Surface & Interface Analysis

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“…Another strategy to measure at lower potential consists to use other mediators as Prussian blue [7,8], Meldola blue [9], ferrocene [10,11] or ferrocyanide [12,13]. Nanomaterials as gold nanoparticles [14,15], carbon nanotubes [16] have also been used in order to improve the electronic transfer between the electroactive center of the enzyme and the surface electrode (3 rd generation sensor) [17]. These sensors would not need any mediator but in the most of the cases, those sensors with nanogolds or nanotubes need some compound as mediator [18,19], which can offer an improvement of sensitivity.…”

Section: Introductionmentioning

confidence: 99%

Enzymatic Sensor Using Mediator‐Screen‐Printed Carbon Electrodes

et al. 2010

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A new glucose sensor was developed using screen-printed ferrocyanide/carbon electrodes. The ferrocyanide is included in the carbon ink of the commercial screen-printed electrode. The immobilization of enzymes glucose oxidase (Gox) and horseradish peroxidase (HRP) were carried out in a very easy way. An aliquot of 10 mL of a Gox/ HRP mixture was deposited on the electrode surface and left there until dried (approximately 1 h) at room temperature. The ferricyanide generated enzymatically was detected amperometrically applying a potential of À0.1 V (vs. Ag pseudo reference electrode). The sensor, so constructed, shows a good sensitivity to glucose (À2.12 mA/mM) with a slope deviation of AE 0.06 mA/mM and a linear range comprised between 0.05 and 1 mM of glucose, with a limit of detection of 0.025 mM. These sensors show good intersensor reproducibility and a high stability. When they are stored at 4 8C, no significant changes in the slope value of the glucose calibration plot were found after 3 months. Glucose was determined in real samples as honey, blood, drink for babies and glucosed drink with a great accuracy.

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“…Nanomaterials, with their unique and excellent properties such as large surface area and good biocompatibility, have been utilized as the film-forming materials to immobilize GOD on electrodes. For example, GOD in the films of Au colloids [15], CdS nanoparticles [16], CN x nanotubes [17], TiO 2 nanoparticles [18], and carbon nanotubes [19 -21] has exhibited a pair of quasi-reversible cyclic voltammetric (CV) peaks for FAD/ FADH 2 couples. However, since the enzyme may undergo serious structure change during its immobilization on the surface of electrodes, and its bioactivity may be weakened or even destroyed in the immobilization procedure [22 -24], it is still a great challenge to create novel surfaces that can fix GOD firmly without altering its original conformation and bioactivity.…”

Section: Introductionmentioning

confidence: 99%

Study on Direct Electrochemistry of Glucose Oxidase Stabilized by Cross‐Linking and Immobilized in Silica Nanoparticle Films

Liu

2007

Electroanalysis

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Glucose oxidase (GOD) in SiO 2 nanoparticle films was cross-linked by glutaraldehyde (GA), forming GOD-GA-SiO 2 films on the surface of pyrolytic graphite (PG) electrodes. GOD in the GOD-GA-SiO 2 films showed a pair of well defined and quasi-reversible cyclic voltammetric peaks at À 0.48 V vs. SCE in pH 7.0 buffers. Scanning electron microscopy of the films demonstrated that the interaction between GOD and GA/SiO 2 would make the morphology of dry GOD-GA-SiO 2 films very different from that of SiO 2 and GOD-SiO 2 films. IR spectroscopy confirms that the GODs in the films are indeed cross-linked through GA, and GA in the films greatly improves the film stability. UVvis and IR spectroscopy suggest that the enzyme is not denatured by cross-linking in the films. The comparative bioelectrocatalytic study with free flavin adenine dinucleotide (FAD) in SiO 2 films indicates that GOD in the films retains its biocatalytic activity toward glucose oxidation. All these results show that SiO 2 nanoparticle films not only provide a favorable microenvironment for the native GOD to exchange electrons directly with underlying electrodes, but also supply a matrix for stabilizing GOD when combined with GA.

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Third-generation biosensors based on TiO2 nanostructured films

Cited by 95 publications

References 17 publications

Immobilization of GOD and HRP enzymes on nanostructured substrates

Immobilization of GOD and HRP enzymes on nanostructured substrates

Enzymatic Sensor Using Mediator‐Screen‐Printed Carbon Electrodes

Study on Direct Electrochemistry of Glucose Oxidase Stabilized by Cross‐Linking and Immobilized in Silica Nanoparticle Films

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