Femtomolar Detection of Silver Nanoparticles by Flow-Enhanced Direct-Impact Voltammetry at a Microelectrode Array

Sokolov, Stanislav V.; Bartlett, Thomas R.; Fair, Peter; Fletcher, Stephen; Compton, Richard G.

doi:10.1021/acs.analchem.6b02670

Cited by 35 publications

(27 citation statements)

References 41 publications

(76 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nanoparticle collisions at an electrode surface can support direct electron transfer, thereby permitting examination of the heterogeneous electron transfer kinetics of nanoparticles with fast response times and high signal‐to‐noise ratios . A single nanoparticle colliding on the electrode surface can also block the electrode from transferring charge (if the nanoparticle is not redox active), serve as an active‐site for electrocatalytic reaction, or initiate direct redox reactions involving the nanoparticle species . Xiao and Bard first characterized single nanoparticle collisions on an ultramicroelectrode by recording the current transients from electrocatalytic reactions in the presence of nanoparticles .…”

Section: Introductionmentioning

confidence: 99%

Voltage‐Gated Nanoparticle Transport and Collisions in Attoliter‐Volume Nanopore Electrode Arrays

Han

Crouch

et al. 2018

Small

View full text Add to dashboard Cite

Single nanoparticle analysis can reveal how particle‐to‐particle heterogeneity affects ensemble properties derived from traditional bulk measurements. High‐bandwidth, low noise electrochemical measurements are needed to examine the fast heterogeneous electron‐transfer behavior of single nanoparticles with sufficient fidelity to resolve the behavior of individual nanoparticles. Herein, nanopore electrode arrays (NEAs) are fabricated in which each pore supports two vertically spaced, individually addressable electrodes. The top ring electrode serves as a particle gate to control the transport of silver nanoparticles (AgNPs) within individual attoliter volume NEAs nanopores, as shown by redox collisions of AgNPs collisions at the bottom disk electrode. The AgNP‐nanoporeis system has wide‐ranging technological applications as well as fundamental interest, since the transport of AgNPs within the NEA mimics the transport of ions through cell membranes via voltage‐gated ion channels. A voltage threshold is observed above which AgNPs are able to access the bottom electrode of the NEAs, i.e., a minimum potential at the gate electrode is required to switch between few and many observed collision events on the collector electrode. It is further shown that this threshold voltage is strongly dependent on the applied voltage at both electrodes as well as the size of AgNPs, as shown both experimentally and through finite‐element modeling. Overall, this study provides a precise method of monitoring nanoparticle transport and in situ redox reactions within nanoconfined spaces at the single particle level.

show abstract

Section: Introductionmentioning

confidence: 99%

Voltage‐Gated Nanoparticle Transport and Collisions in Attoliter‐Volume Nanopore Electrode Arrays

Han

Crouch

et al. 2018

Small

View full text Add to dashboard Cite

show abstract

“…Femtomolar concentrations of AgNPs have been detected by direct impact voltammetry using a random array of microelectrodes integrated into a flow cell. It was shown that under flow conditions, the impact frequency increases linearly with the flow rate, which enhances mass transport by flow . Some reports show good agreement for nanoparticle size measurements between the collision experiments, electron microscopy and light scattering techniques …”

Section: Analytical Information That Can Be Extracted From Single‐entmentioning

confidence: 99%

Electroanalytic Aspects of Single‐Entity Collision Methods for Bioanalytical and Environmental Applications

et al. 2018

View full text Add to dashboard Cite

entity electrochemistry based on measurements of collision events at electrode surfaces is a rapidly developing field which provides extensive capabilities for detection and characterization of a variety of materials including organic and inorganic nanoparticles (NPs) and nanostructures as well as biologicals. The method has demonstrated promising potential for the analysis of catalytic activity, physicochemical parameters, fundamental surface properties, functionalization and reactivity of NPs. Here, the most recent developments and capabilities of this method as a novel tool for characterizing nanoscale properties are discussed, illustrating novel applications for assessing bioconjugation, designing ultrasensitive biosensing methods and monitoring processes of biological and environmental significance. The main advantages and limitations as compared to commonly used spectroscopy and imaging techniques are described, highlighting areas in which collision measurements can be used as a complementary approach to characterize properties of inorganic NPs, organic molecules, soft materials and biologicals, and develop methodologies for detection and quantification of analytes of interest in the bioanalytical, biological and environmental fields. An overview of potential applications in these fields is provided along with a critical discussion of future research needs and opportunities.

show abstract

“…Electrochemical detection of gold nanoparticles in flow based on more complex reaction path including electrocatalytic reaction was also reported . Electrochemical detection of Ag nanoparticles in flow based on their electrodissolution was also examined . Apart from fundamental aspects , such studies are of practical importance, because of the increasing amounts of nanomaterials released to the environment and their potential toxicity .…”

Section: Introductionmentioning

confidence: 99%

Electrochemical Detection of Positively Charged Carbon Nanoparticles Suspension in Flow

et al. 2018

View full text Add to dashboard Cite

The electrochemical behaviour of suspended nanoparticles received some attention recently. Very few studies are performed in the flow system. Here, we have demonstrated that injection of positively charged (with ammonium functionalities) carbon nanoparticles suspension to flowing ascorbic acid solution significantly enhances its chronoamperometric response and can be used for these nanoparticles detection. This is because of electrocatalytic properties of these nanoparticles towards ascorbic acid electrooxidation. The magnitude of the signal depends on the type of flow system and is larger than in the case of suspension of negatively charged nanoparticles. It is also proportional to the concentration of nanoparticles. Their adsorption on the electrode surface plays the crucial role in the electrode process.

show abstract

Femtomolar Detection of Silver Nanoparticles by Flow-Enhanced Direct-Impact Voltammetry at a Microelectrode Array

Cited by 35 publications

References 41 publications

Voltage‐Gated Nanoparticle Transport and Collisions in Attoliter‐Volume Nanopore Electrode Arrays

Voltage‐Gated Nanoparticle Transport and Collisions in Attoliter‐Volume Nanopore Electrode Arrays

Electroanalytic Aspects of Single‐Entity Collision Methods for Bioanalytical and Environmental Applications

Electrochemical Detection of Positively Charged Carbon Nanoparticles Suspension in Flow

Contact Info

Product

Resources

About