Time-Resolved Electrochemical Detection of Discrete Adsorption Events

Quinn, Bernadette M.; Hof, Pieter G. Van 'T; Lemay, Serge G.

doi:10.1021/ja0478577

Cited by 244 publications

(358 citation statements)

References 12 publications

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“…2D. If the conjugation is incomplete or the antibody is not specific to the virus, no preconcentration occurs, and blocking will be observed, consistent with numerous examples of blocking in the literature (18)(19)(20). When the virus carries thousands of GOx enzymes to the electrode, feedback is generated, creating a discrete, positive current response.…”

supporting

confidence: 59%

Enzymatically enhanced collisions on ultramicroelectrodes for specific and rapid detection of individual viruses

Dick

Hilterbrand

Strawsine

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

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We report the specific collision of a single murine cytomegalovirus (MCMV) on a platinum ultramicroelectrode (UME, radius of 1 μm). Antibody directed against the viral surface protein glycoprotein B functionalized with glucose oxidase (GOx) allowed for specific detection of the virus in solution and a biological sample (urine). The oxidation of ferrocene methanol to ferrocenium methanol was carried out at the electrode surface, and the ferrocenium methanol acted as the cosubstrate to GOx to catalyze the oxidation of glucose to gluconolactone. In the presence of glucose, the incident collision of a GOx-covered virus onto the UME while ferrocene methanol was being oxidized produced stepwise increases in current as observed by amperometry. These current increases were observed due to the feedback loop of ferrocene methanol to the surface of the electrode after GOx reduces ferrocenium methanol back to ferrocene. Negative controls (i) without glucose, (ii) with an irrelevant virus (murine gammaherpesvirus 68), and (iii) without either virus do not display these current increases. Stepwise current decreases were observed for the prior two negative controls and no discrete events were observed for the latter. We further apply this method to the detection of MCMV in urine of infected mice. The method provides for a selective, rapid, and sensitive detection technique based on electrochemical collisions.collisions | cytomegalovirus | electrochemistry | electrovirology | ELISA T he development of methods to observe collisions on ultramicroelectrodes (UMEs) has allowed for the study of single entities, such as single nanoparticles (1), emulsion droplets (2, 3), vesicles (4, 5), biological macromolecules (6), and even single ions (7), in a digital manner (8). However, many of the techniques developed lack specificity. In the field of collisions, the study of biologically relevant analytes of interest, such as viruses and cells, has been largely unexplored. Perhaps the greatest challenges in these experiments are achieving specificity and understanding the electrochemical response. Overcoming these challenges will ultimately lead to the development of sensitive detection methodologies based on facile and inexpensive electrochemical methods, which will be of importance in the diagnosis of infectious diseases.Rapid, accurate diagnosis is a critical first step in the care of those suffering from viral infections. ELISAs, PCR-based techniques, or culture methods are fairly reliable diagnostic measures with varying degrees of sensitivity (9-11). However, these diagnostic techniques require a significant degree of sample and experimental preparation, increasing the amount of time between a positive diagnosis and the beginning of treatment. Diagnostic tools that are able to directly sample from complex media (i.e., blood, serum, urine, etc.) are necessary to expedite the diagnostic process.One such infectious agent that requires rapid and early detection is human cytomegalovirus (HCMV). HCMV is a prototypical betaherpesvirus, establ...

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supporting

confidence: 59%

Enzymatically enhanced collisions on ultramicroelectrodes for specific and rapid detection of individual viruses

Dick

Hilterbrand

Strawsine

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

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“…1−9 So far, most single-particle collision experiments have been focused on "hard" particles such as metal nanoparticles (Pt, Au, Cu, Ag), 1−5 oxides (IrO 2 , TiO 2 ), 6,7 and dielectrics (polystyrene, SiO 2 ). 8,9 Recently, we extended the single-particle collision research to "soft" (or "liquid") particles such as emulsions. Previously, we proposed two kinds of new methods to study single soft particle collisions in emulsions.…”

Section: Introductionmentioning

confidence: 99%

Electrochemistry of a Single Attoliter Emulsion Droplet in Collisions

2015

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We report here the electrochemistry of emulsion droplets by observing single emulsion droplet collisions with selective electrochemical reduction on an ultramicroelectrode (UME). With appropriately applied potentials at an UME, we can observe the electrochemical effects of single collision signals from the complete electrolysis of single emulsion droplets, or selective electrolysis of redox species in single emulsion droplets. This was observed with nitrobenzene (NB), 7,7,8,8-tetracyanoquinodimethane (TCNQ), and ionic liquid. The NB, TCNQ, and ionic liquid act as emulsion material, redox specie, and emulsifier (and electrolyte), respectively. NB emulsions and NB (TCNQ) emulsions were made by ultrasonic processing. During the amperometric current-time (i-t) curve measurement with NB/water emulsion at -0.65 V, reduction of NB emulsion droplets was measured. In the case of less negative potentials, e.g., at -0.45 V with a NB (TCNQ) emulsion, selective reduction of TCNQ in NB droplet was measured. Spike-like responses from electrolysis of NB or TCNQ in each experiment were observed. From these single-particle collision results of NB and NB (TCNQ) emulsions, the collision frequency, size distribution, i-t decay behavior of emulsion droplets, and possible mechanisms are discussed.

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“…By observing the collisions of small particles, there is the possibility that information can be deduced that is not available in ensemble measurements. The electrochemical study of single collision events has been applied to a wide range of hard nanoparticles (NPs), which include metal, metal oxide, and organic NPs [platinum (1), silver (2), gold (3), nickel (4), copper (5), iridium oxide (6), cerium oxide (7), titanium oxide (8), silicon oxide (9), indigo (10), polystyrene (11), and relatively large aggregates of fullerene (12)]. Recently, collisions of soft particles have been investigated, such as toluene droplets (13) and liposomes (14).…”

mentioning

confidence: 99%

Electrochemical detection of a single cytomegalovirus at an ultramicroelectrode and its antibody anchoring

Dick

Hilterbrand

Boika

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

147

132

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We report observations of stochastic collisions of murine cytomegalovirus (MCMV) on ultramicroelectrodes (UMEs), extending the observation of discrete collision events on UMEs to biologically relevant analytes. Adsorption of an antibody specific for a virion surface glycoprotein allowed differentiation of MCMV from MCMV bound by antibody from the collision frequency decrease and current magnitudes in the electrochemical collision experiments, which shows the efficacy of the method to size viral samples. To add selectivity to the technique, interactions between MCMV, a glycoprotein-specific primary antibody to MCMV, and polystyrene bead "anchors," which were functionalized with a secondary antibody specific to the Fc region of the primary antibody, were used to affect virus mobility. Bead aggregation was observed, and the extent of aggregation was measured using the electrochemical collision technique. Scanning electron microscopy and optical microscopy further supported aggregate shape and extent of aggregation with and without MCMV. This work extends the field of collisions to biologically relevant antigens and provides a novel foundation upon which qualitative sensor technology might be built for selective detection of viruses and other biologically relevant analytes.collisions | cytomegalovirus | electrochemistry | murine cytomegalovirus | virus O ver the past decade, the study of discrete collision events on ultramicroelectrodes (UMEs) has gained attention due to the interest in understanding stochastic phenomena by electrochemistry. By observing the collisions of small particles, there is the possibility that information can be deduced that is not available in ensemble measurements. The electrochemical study of single collision events has been applied to a wide range of hard nanoparticles (NPs), which include metal, metal oxide, and organic NPs [platinum (1), silver (2), gold (3), nickel (4), copper (5), iridium oxide (6), cerium oxide (7), titanium oxide (8), silicon oxide (9), indigo (10), polystyrene (11), and relatively large aggregates of fullerene (12)]. Recently, collisions of soft particles have been investigated, such as toluene droplets (13) and liposomes (14). Also, collisions of toluene and tri-n-propylamine droplets were observed simultaneously by both electrochemical and electrogenerated chemiluminescent (ECL) measurements (15).Similarly, a variety of techniques have been developed to observe these collision events. The interested reader can consult the references for a discussion on each of the techniques used to observe stochastic events electrochemically: blocking (9, 13), electrocatalytic amplification (1), open circuit potential (16), droplet blocking/reactor (13,14), and ECL (15,17,18). The simplest and most reproducible method of observing collisions is a technique termed blocking, which is so named because particles, which are brought to the electrode by a diffusion-limited flux and/or electrophoretic migration, irreversibly adsorb (1) to the electrode surface, blocking the flux of red...

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Time-Resolved Electrochemical Detection of Discrete Adsorption Events

Abstract: Individual binding events are observed using amperometric detection. Discrete steps in the microelectrode amperometric response correspond to the adsorption of single microspheres on the electrode surface.

Cited by 244 publications

References 12 publications

Enzymatically enhanced collisions on ultramicroelectrodes for specific and rapid detection of individual viruses

Enzymatically enhanced collisions on ultramicroelectrodes for specific and rapid detection of individual viruses

Electrochemistry of a Single Attoliter Emulsion Droplet in Collisions

Electrochemical detection of a single cytomegalovirus at an ultramicroelectrode and its antibody anchoring

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