Localized Visualization of Chemical Cross-Talk in Microsensor Arrays by Using Scanning Electrochemical Microscopy

Strike, D. J.; Hengstenberg, Andreas; Quinto, Maurizio; Kurzawa, Christian; Koudelka‐Hep, M.; Schuhmann, Wolfgang

doi:10.1007/s006040050008

Cited by 26 publications

(16 citation statements)

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“…Since the center-to-center distance between the 20 mm Â 20 mm microelectrodes was only 80 mm in the imaged MEA (Fig. 1A), in accordance with the theory [12,17,45,46] the diffusion layers of the adjacent microelectrode sites slightly overlap [47].…”

Section: Secm Imaging Of Gold Mea Surfaces With and Without Immobilizmentioning

confidence: 61%

Microfabricated Amperometric Cells for Multicomponent Analysis

et al. 2009

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Towards the development of multianalyte electrochemical immunoassays three individually addressable microelectrode array (MEA) type working electrodes and a reference electrode were integrated into a 4 mL volume, planar electrochemical cell. To model the simultaneous determination of multiple antigens in the cell with enzyme linked immunosorbent assays (ELISAs) glucose oxidase (GOx), alkaline phosphatase (ALP), and b-galactosidase (b-GAL) were immobilized site specifically onto the individual MEA surfaces and the biocatalitic activity of these surface confined enzymes were evaluated by measuring the products of the enzyme catalyzed reactions directly on the gold MEA surfaces by chronoamperometry or by imaging the enzyme patterned microelectrode array surfaces by Scanning Electrochemical Microscopy (SECM). ALP and b-GAL were selected as model enzymes because they are the most commonly used enzymes labels in ELISAs. In these measurements glucose, ascorbic acid phosphate (AAP), and p-aminophenyl-b-d-galactopyranoside (PAPG) served as enzyme substrates, respectively. The electrochemical surface area of the gold MEAs did not change during the multistep immobilization process. All enzyme modified MEAs presented selective and proportional responses to their substrates and the response characteristics of the enzyme modified sensors were identical in separate and simultaneous calibration protocols, i.e., there was no crosscontamination between the closely placed MEAs. The SECM images of the enzyme patterned MEA surfaces suggest that nonspecific adsorption is negligible on the insulating polyimide surface of the MEA separating the individual microelectrode sites.

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Section: Secm Imaging Of Gold Mea Surfaces With and Without Immobilizmentioning

confidence: 61%

Microfabricated Amperometric Cells for Multicomponent Analysis

et al. 2009

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“…H 2 O 2 as produced by glucose oxidase in the presence of glucose). Various applications of this imaging mode were published recently (Horrocks et al, 1993;Kasai et al, 2002;Wittstock and Schuhmann, 1997;Kranz et al, 1997;Strike et al, 1999;Wittstock, 2001;Horrocks and Wittstock, 2001a).…”

Section: Introductionmentioning

confidence: 99%

Visualization of micropatterned complex biosensor sensing chemistries by means of scanning electrochemical microscopy

Niculescu

Gáspár

Schulte

et al. 2004

Biosensors and Bioelectronics

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“…Regeneration of the reduced form of the mediator is enhancing the current through the ultramicroelectrode as compared to tip positions over areas without enzyme coverage (Pierce and Bard, 1993;Zhou et al, 2002). Alternatively, in the sample-generation-tip-collection mode of SECM (Zhou et al, 1992;Martin and Unwin, 1998) localized chemical activity can be visualized conveniently based on the detection of an electroactive species (e.g., the product of an enzymatic reaction) released from the surface by its electrochemical conversion at the SECM tip (Pierce and Bard, 1993;Wittstock and Schuhmann, 1997;Strike et al, 1999;Wittstock, 2001;Kasai et al, 2002;Zhao and Wittstock, 2004). First attempts to use the spatial inhomogeneity of enzyme microstructures for extracting increased information were demonstrated recently (Gáspár et al, 2001;Turcu et al, 2005).…”

Section: Introductionmentioning

confidence: 99%