Improving the performance of electrochemical microsensors based on enzymes entrapped in a redox hydrogel

Mitala, Joseph; Michael, A.C.

doi:10.1016/j.aca.2005.09.053

Cited by 37 publications

(23 citation statements)

References 39 publications

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“…The sensitivity of design 6 was slightly less in the presence of 400 M AA (∼20%) than in PBS alone, but the difference was not significant (p > 0.8, paired t-test, n = 6). This modest decrease in the H 2 O 2 signal caused by large excesses of AA is similar to that reported for redox hydrogel-based biosensors (Mitala and Michael, 2006;Oldenziel et al, 2006). Since it is not possible at present to determine absolute ECF levels of an analyte using in situ electrochemical techniques, these sensors are designed to monitor continuous changes in H 2 O 2 concentrations.…”

Section: Hydrogen Peroxide Sensitivity In the Presence Of Ascorbic Acidsupporting

confidence: 66%

Development and characterization in vitro of a catalase-based biosensor for hydrogen peroxide monitoring

O'Brien¹,

Killoran²,

O’Neill³

et al. 2007

Biosensors and Bioelectronics

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There is increasing evidence that hydrogen peroxide (H 2 O 2 ) may act as a neuromodulator in the brain, as well as contributing to neurodegeneration in diseased states, such as Parkinson's disease. The ability to monitor changes in endogenous H 2 O 2 in vivo with high temporal resolution is essential in order to further elucidate the roles of H 2 O 2 in the central nervous system. Here, we describe the in vitro characterization of an implantable catalase-based H 2 O 2 biosensor. The biosensor comprises two amperometric electrodes, one with catalase immobilized on the surface and one without enzyme (blank). The analytical signal is then the difference between the two electrodes. The H 2 O 2 sensitivity of various designs was compared, and ranged from 0 to 56 ± 4 mA cm −2 M −1 . The most successful design incorporated a Nafion ® layer followed by a poly-o-phenylenediamine (PPD) polymer layer. Catalase was adsorbed onto the PPD layer and then cross-linked with glutaraldehyde. The ability of the biosensors to exclude interference from ascorbic acid, and other interference species found in vivo, was also tested. A variety of the catalase-based biosensor designs described here show promise for in vivo monitoring of endogenous H 2 O 2 in the brain.

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Section: Hydrogen Peroxide Sensitivity In the Presence Of Ascorbic Acidsupporting

confidence: 66%

Development and characterization in vitro of a catalase-based biosensor for hydrogen peroxide monitoring

O'Brien¹,

Killoran²,

O’Neill³

et al. 2007

Biosensors and Bioelectronics

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show abstract

“…As well as possessing the appropriate level of biocompatibility, implantable oxidase-based biosensors must also fulfill the following minimum criteria for reliable analyte monitoring: appropriate size and geometry [32,33]; good sensitivity to the enzyme substrate [34]; effective rejection of electroactive interference [35,36]; and, low sensitivity to changes in pO 2 over the range of substrate and oxygen concentrations relevant to the intended application [11,37]. Even different tissues present distinct challenges.…”

Section: Designs Of Biosensors For Brain Implantationmentioning

confidence: 99%

Designing sensitive and selective polymer/enzyme composite biosensors for brain monitoring in vivo

O’Neill

Rocchitta

McMahon

et al. 2008

TrAC Trends in Analytical Chemistry

118

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Amperometric polymer/enzyme composite (PEC) biosensors, incorporating a poly(o-phenylenediamine) ultra-thin permselective barrier, possess a variety of characteristics that make them suitable for monitoring brain energy and neurotransmitter dynamics in vivo. This review highlights PEC sensitivity and selectivity parameters, which allow development of the basic design in a systematic way in order to improve their performance and to diversify the analyte range of these novel probes of brain function. ª

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“…In applications, such as electronic biosensors, it is important that the entrapped enzymes are not denaturated and remain in their active state. Otherwise, the sensitivity and selectivity of the biosensor is decreased drastically [250,251,252,253]. Mao et al introduced a new redox hydrogel, consisting of a polymer with 13-atom-long tethers between the redox centers and the polymer backbone.…”

Section: Hydrogelmentioning

confidence: 99%

Electrochemical Biosensors - Sensor Principles and Architectures

Grieshaber

MacKenzie

Vörös

et al. 2008

Sensors

839

636

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Quantification of biological or biochemical processes are of utmost importance for medical, biological and biotechnological applications. However, converting the biological information to an easily processed electronic signal is challenging due to the complexity of connecting an electronic device directly to a biological environment. Electrochemical biosensors provide an attractive means to analyze the content of a biological sample due to the direct conversion of a biological event to an electronic signal. Over the past decades several sensing concepts and related devices have been developed. In this review, the most common traditional techniques, such as cyclic voltammetry, chronoamperometry, chronopotentiometry, impedance spectroscopy, and various field-effect transistor based methods are presented along with selected promising novel approaches, such as nanowire or magnetic nanoparticle-based biosensing. Additional measurement techniques, which have been shown useful in combination with electrochemical detection, are also summarized, such as the electrochemical versions of surface plasmon resonance, optical waveguide lightmode spectroscopy, ellipsometry, quartz crystal microbalance, and scanning probe microscopy. The signal transduction and the general performance of electrochemical sensors are often determined by the surface architectures that connect the sensing element to the biological sample at the nanometer scale. The most common surface modification techniques, the various electrochemical transduction mechanisms, and the choice of the recognition receptor molecules all influence the ultimate sensitivity of the sensor. New nanotechnology-based approaches, such as the use of engineered ion-channels in lipid bilayers, the encapsulation of enzymes into vesicles, polymersomes, or polyelectrolyte capsules provide additional possibilities for signal amplification. In particular, this review highlights the importance of the precise control over the delicate interplay between surface nano-architectures, surface functionalization and the chosen sensor transducer principle, as well as the usefulness of complementary characterization tools to interpret and to optimize the sensor response.

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Improving the performance of electrochemical microsensors based on enzymes entrapped in a redox hydrogel

Cited by 37 publications

References 39 publications

Development and characterization in vitro of a catalase-based biosensor for hydrogen peroxide monitoring

Development and characterization in vitro of a catalase-based biosensor for hydrogen peroxide monitoring

Designing sensitive and selective polymer/enzyme composite biosensors for brain monitoring in vivo

Electrochemical Biosensors - Sensor Principles and Architectures

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