Urease–gelatin interdigitated microelectrodes for the conductometric determination of protease activity

Ionescu, Rodica Elena; Fillit, Chrystelle; Jaffrézic‐Renault, Nicole; Cosnier, Serge

doi:10.1016/j.bios.2008.06.021

Cited by 28 publications

(15 citation statements)

References 17 publications

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“…Series of more sensitive and faster electrochemical sensors for trypsin activity determination were developed by Biloivan et al [14] Ionescu et al [15,16], Fordyce et al [17], Adjemian et al [18], Baş et al [19], Stoytcheva et al [20], Chen et al [6] with conductometric, amperometric, voltammetric, and potentiometric detection.…”

Section: Introductionmentioning

confidence: 99%

Nanoparticles Amplified QCM Sensor for Enzyme Activity Evaluation

et al. 2015

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This investigation introduces a new very simple and efficient approach for QCM sensor response amplification, developed for hydrolases activity determination. For this purpose, the QCM crystal surface was modified with nanoparticles loaded enzyme substrate. During the enzymatic substrate degradation, the heavier nanoparticles were also released from the sensitive layer together with the substrate degradation products. Nanoparticles removal resulted in QCM signal amplification due to the higher nanoparticles specific mass compared with the specific mass of the substrate.The suggested concept was successfully applied for creating of simple biosensing platforms for trypsin and lipase activity determination in real time using respectively SiO 2 nanoparticles loaded olive oil and Ag nanoparticles loaded gelatin as enzyme substrates. Up to 10 times amplification of the QCM signal was reached applying the proposed approach compared with the common one.

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Section: Introductionmentioning

confidence: 99%

Nanoparticles Amplified QCM Sensor for Enzyme Activity Evaluation

et al. 2015

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“…electrochemical assays enable to measurement within turbid and complex media in contrast to the spectrophotometric and fluorimetric assays. Moreover, electrochemical assays promise various detection methods namely amperometric [15 -17], potentiometric [18,20], conductometric [21] and AC impedance [22,23].…”

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Rapid Method for Quantitative Determination of Proteolytic Activity with Cyclic Voltammetry

Baş

Boyaci

2010

Electroanalysis

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An alternative electrochemical method for the determination of proteolytic activity based on cyclic voltammetry of the electroactive probe ferricyanide (Fe(CN) 6 3À ) on the gelatin film coated ITO electrodes was proposed. The gelatin film behaves as a kinetic barrier for Fe(CN) 6 3À and the proteolytic digestion of the gelatin film results an increase in the penetration of the Fe (CN Herein we report an alternative electrochemical method for the determination of proteolytic activity based on cyclic voltammetry (CV) of the electroactive probe ferricyanide (Fe(CN) 6 3À ) on the gelatin film coated ITO electrodes. The gelatin film on the working electrode behaves as a kinetic barrier and thus, penetration of Fe(CN) 6 3À decreased through the gelatin film. The proteolytic digestion of the gelatin film results an increase in the penetration of Fe(CN) 6 3À and the activity of the enzyme was quantified by following the change in the cyclic voltammogram of Fe(CN) 6 3À . Protease activity was determined by using the change in cyclic voltammogram of the electroactive probe ferricyanide (Fe(CN) 6 3À ) on the gelatin film coated ITO electrodes. It is well known that CV of an electroactive probe such as Fe(CN) 6 3À is a useful tool for testing the kinetic barrier of the interface [24,25]. Our approach was based on the decrease in the penetration of Fe(CN) 6 3À through the gelatin film which behaves as a kinetic barrier. Gelatin film as a kinetic barrier decreases the electron transfer between the electrode surface and the electroactive probe, Fe(CN) 6 3À . Electron transfer resistance of the electrode increases upon coating with the gelatin film, and the access of the electroactive probe to the electrode surface is hindered. As a result of increased electron transfer resistance, a decrease in peak current and an increase in the separation of peak potentials are observed in the cyclic voltammogram of the electroactive probe.In the presence of protease enzyme, the gelatin is hydrolyzed, cleavage of peptide bounds, and the structure of the gelatin film on the electrode is changed. The structural change in the semi-solid colloid gel increases the penetration of Fe(CN) 6 3À and thus, an increase in peak current and a decrease in the separation of peak potentials are observed in the cyclic voltammogram of the electroactive probe. In accordance with these facts, the change in the reduction peak potential was monitored and the peak potential vs. time graph was plotted. The enzymatic activity was determined by using the slope of this curve. Figure 1A shows the difference of cyclic voltammograms of Fe(CN) 6 3À both on the bare ITO and gelatin coated ITO electrodes. The gelatin film on the electrode behaves as a kinetic barrier and thus, the irreversibility of the system was increased. In other words, a decrease in peak current and an increase in the separation of peak potentials were observed.Figures 1B and 1C depict the cyclic voltammograms of Fe(CN) 6 3À on the gelatin coated electrodes in the absence and presence of proteas...

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“…Its determination represents a highly specific and reliable test for pancreatitis function diagnostics. Ionescu et al 12,13 report two types of sensitive and rapid electrochemical sensors. In contrast, the electrochemical sensors for trypsin quantification, despite of the simplicity, sensitivity, and the rapidity of the electrochemical detection, are only few until now.…”

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confidence: 99%

“…Nevertheless, the described sensors involve multistep processes [11][12][13] or are not enough sensitive. 14 Thus, in the present work, a novel simple, rapid, and sensitive square wave voltammetric method for trypsin activity determination is reported.…”

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confidence: 99%