Sensitivity enhancement by carbon nanotubes: Applications to stem cell cultures monitoring

Boero, Cristina; Carrara, Sandro; Micheli, Giovanni De

doi:10.1109/rme.2009.5201362

Cited by 15 publications

(13 citation statements)

References 10 publications

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“…2: the reported data correspond to a limited sensitivity per unit area equal to 5.5 ± 1.4 A/mM ×cm 2 for the calibration on bare SPE, while the sensitivity increases to 28.1 ± 9.8 A/mM ×cm 2 on MWCNT electrodes. The Cottrell effect is here about a factor 5x, which is coherent with other similar values previously obtained on the same kind of structured SPE [60]. The sensitivity for hydrogen peroxide detection has also been ameliorated up to 70.7 A/mM ×cm 2 by immobilizing the peroxidase on glassy carbon electrodes structured with MWCNT embedded in chitosan polymer [32].…”

Section: Cottrell Effectsupporting

confidence: 88%

Do Carbon Nanotubes contribute to Electrochemical Biosensing?

Carrara

Baj-Rossi

Boero

et al. 2014

Electrochimica Acta

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a b s t r a c tCarbon nanotubes have been attracting a lot of interest as electron transfer mediators to enhance electrochemical biosensing. The main reason behind this is usually recognized in terms of augmented electrochemical active surface area. The aim of this paper is to review other phenomena that occur at the electrochemical interface. Three distinct features of these phenomena mainly appear in electrochemical biosensing. We introduce the Cottrell, Randle-Sevčick, and Nernst effects to address these features. By using these features, several electrochemical biosensing systems are investigated. Differences among the proposed systems are presented and analyzed in light of these effects. We finally have demonstrated that carbon nanotubes may induce completely opposite effects when dealing with different biosensing systems. This paper also shows that even seemingly small differences (e.g., changing metabolite as detected by the same enzyme) might result in opposite effects on the same carbon nanotube based sensor. Nevertheless, it is shown that carbon nanotubes, in some cases, confirm their exceptional nature in enhancing the sensor performance by orders of magnitude. The sensitivity increases from 87 ± 62 to 3718 ± 73 nA/M ×cm 2 and detection limit decreases from 7.5 ± 5.3 mM to 84 ± 2 M in case of cyclophosphamide detected by the cytochromes P450 3A4.

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Section: Cottrell Effectsupporting

confidence: 88%

Do Carbon Nanotubes contribute to Electrochemical Biosensing?

Carrara

Baj-Rossi

Boero

et al. 2014

Electrochimica Acta

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“…Each biosensor was washed with Milli-Q water and then rinsed before experiments. Control experiments (MWCNT-SPEs and H 2 O 2 [20], MWCNT-SPEs and l-lactate [21], enzyme adsorbed on SPEs and l-lactate [21]) confirm that l-lactate electrochemical detection drastically improves by the use of MWCNTs with adsorbed l-lactate oxidase.…”

Section: Electrode Preparationmentioning

confidence: 69%

Comparative study of three lactate oxidases from Aerococcus viridans for biosensing applications

Taurino

Reiss

Richter

et al. 2013

Electrochimica Acta

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Keywords:l-Lactate oxidases from Aerococcus viridans Engineered and commercial enzymes Multi-walled carbon nanotubes Enzyme biosensor a b s t r a c t A comparison between engineered and commercially available l-lactate oxidases from Aerococcus viridans was conducted for biosensing applications. Enzymes were adsorbed onto the surfaces of graphite electrodes modified with multi-walled carbon nanotubes. Thermostable l-lactate oxidases were cloned with a (i) N-, (ii) a C-terminal His-tag and (iii) a wild-type enzyme. Subsequently to the heterologous expression in Escherichia coli and purification, we determined the kinetic parameters of these enzymes in solution. The kinetics of the wild-type, of the N-terminally His-tagged enzyme and of the commercial l-lactate oxidase from A. viridans were studied with a classical Michaelis-Menten as well as with a substrate inhibition model, while the enzyme carrying a C-terminal His-tag showed no activity. The active enzymes were used to fabricate and comparatively investigate multi-walled carbon nanotubes-based biosensors. The enzyme kinetic results were compared with electrochemical studies. By using both spectrophotometric and amperometric techniques, the inhibition phenomenon fits better to the data especially those data related with Lox-His-N. The electrochemical data of the fabricated enzymatic biosensors showed that the N-terminally His-tagged l-lactate oxidase performed best on carboxyl-modified carbon nanotubes. The sensor based on this engineered enzyme showed the highest sensitivity and lowest detection limit in the range of l-lactate concentration 0-1 mM as well as long term stability over one month.

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“…A volume of 25 l per step of the target molecule is successively added into the solution with a time-step of 2 min. To perform measurements, we apply a potential of +550 mV vs. Ag/AgCl, which corresponds to the oxidation potential of hydrogen peroxide [19]. For glucose biosensor, we obtain a sensitivity of 27.7 A mM −1 cm −2 , a linear range within 0.5-4.0 mM, and detection limit of 73 M (considering a signal-to-noise ratio of 3).…”

Section: Biosensor Calibrationmentioning

confidence: 99%

Targeting of multiple metabolites in neural cells monitored by using protein-based carbon nanotubes

Boero

Carrara

Vecchio

et al. 2011

Sensors and Actuators B: Chemical

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a b s t r a c tMicrodevices dedicated to monitor metabolite levels have recently enabled many applications in the field of cell analysis, to monitor cell growth and development of numerous cell lines. By combining the traditional technology used for electrochemical biosensors with nanoscale materials, it is possible to develop miniaturized metabolite biosensors with unique properties of sensitivity and detection limit. In particular, enzymes tend to adsorb onto carbon nanotubes and their optical or electrical activity can perturb the electronic properties. In the present work we propose multi-walled carbon nanotube-based biosensors to monitor a cell line highly sensitive to metabolic alterations, in order to evaluate lactate production and glucose uptake during different cell states. We achieve sensors for both lactate and glucose, with sensitivities of 40.1 A mM −1 cm −2 and 27.7 A mM −1 cm −2 , and detection limits of 28 M and 73 M, respectively. This nano-biosensing technology is used to provide new information on cell line metabolism during proliferation and differentiation, which are unprecedented in cell biology.

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Sensitivity enhancement by carbon nanotubes: Applications to stem cell cultures monitoring

Cited by 15 publications

References 10 publications

Do Carbon Nanotubes contribute to Electrochemical Biosensing?

Do Carbon Nanotubes contribute to Electrochemical Biosensing?

Comparative study of three lactate oxidases from Aerococcus viridans for biosensing applications

Targeting of multiple metabolites in neural cells monitored by using protein-based carbon nanotubes

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