Single Nanoparticle Collisions at Microfluidic Microband Electrodes: The Effect of Electrode Material and Mass Transfer

Alligrant, Timothy M.; Anderson, Morgan J.; Dasari, Radhika; Stevenson, Keith J.; Crooks, Richard M.

doi:10.1021/la503628h

Cited by 42 publications

(54 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Taking into consideration the observed variance of NTA measurements and inherent bias towards tracking larger NPs more accurately due to higher scattering intensities, we surmise that the solution conditions involving SPB concentrations ≤ 10 mM were sufficiently optimized 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Our group has previously reported on the optimization of electrode materials, Hg in particular, to enhance signal-to-noise and improve time resolution of the ECA response for NP impacts. [43][44][45][46] The fundamental principles ...…”

mentioning

confidence: 99%

Addressing Colloidal Stability for Unambiguous Electroanalysis of Single Nanoparticle Impacts

Robinson

Kondajji

Castañeda

et al. 2016

J. Phys. Chem. Lett.

Self Cite

View full text Add to dashboard Cite

Herein the problem of colloidal instability on electrochemically detected nanoparticle (NP) collisions with a Hg ultramicroelectrode (UME) by electrocatalytic amplification is addressed. NP tracking analysis (NTA) shows that rapid aggregation occurs in solution after diluting citrate-stabilized Pt NPs with hydrazine/phosphate buffers of net ionic strength greater than 70 mM. Colloidal stability improves by lowering the ionic strength, indicating that aggregation processes were strongly affected by charge screening of the NP double layer interactions at high cation concentrations. For the system of lowest ionic strength, the overwhelming majority of observed electrocatalytic current signals represent single NP/electrode impacts, as confirmed by NTA kinetic monitoring. NP diffusion coefficients determined by NTA and NP impact electroanalysis are in excellent agreement for the stable colloids, which signifies that the sticking probability of Pt NPs interacting with Hg is unity and that the observed NP impact rate agrees with the expected steady-state diffusive flux expression for the spherical cap Hg UME.

show abstract

mentioning

confidence: 99%

Addressing Colloidal Stability for Unambiguous Electroanalysis of Single Nanoparticle Impacts

Robinson

Kondajji

Castañeda

et al. 2016

J. Phys. Chem. Lett.

Self Cite

View full text Add to dashboard Cite

show abstract

“…This is the lowest concentration of NPs ever used in a successful nanoimpact experiment, with an enhancement in experimental detectivity by 2 orders of magnitude over earlier attempts 19 and by 1 order of magnitude for mediated impacts . 30 Hitherto, the lowest reported experimentally detected concentration of NPs by direct impacts is 900 fM, using a carbon fiber microwire electrode. 19 Nonspecific adsorption is inherent in NP chemistry and can have an effect on the concentration of NPs in suspension.…”

Section: Resultsmentioning

confidence: 96%

“…29 Recent work has also exploited enhanced mass transport by flow for the detection of NPs via the mediated-impact method and has achieved detection limits of 83 fM. 30 …”

mentioning

confidence: 99%

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

et al. 2016

View full text Add to dashboard Cite

We report the femtomolar detection of silver (Ag) nanoparticles by direct-impact voltammetry. This is achieved through the use of a random array of microelectrodes (RAM) integrated into a purpose-built flow cell, allowing combined diffusion and convection to the electrode surface. A coupled RAM-flow cell system is implemented and is shown to give reproducible wall-jet type flow characteristics, using potassium ferrocyanide as a molecular redox species. The calibrated flow system is then used to detect and quantitatively size Ag nanoparticles at femtomolar concentrations. Under flow conditions, it is found the nanoparticle impact frequency increases linearly with the volumetric flow rate. The resulting limit of detection is more than 2 orders of magnitude smaller than the previous detection limit for direct-impact voltammetry (900 fM) [J. Ellison et al. Sens. Actuators, B2014, 200, 47], and is more than 30 times smaller than the previous detection limit for mediated-impact voltammetry (83 fM) [T. M. Alligrant et al. Langmuir2014, 30, 13462].

show abstract

“…Sensitivity can be increased by coupling an electrocatalytic reaction to the collision event [202]. Alternatively, the frequency of impacts can be increased by driving nanoparticles to the electrode surface not only by Brownian motion, but also by mass transfer [203] or using magnetic fields [204]. The use of cylindrical microelectrodes instead of microdisks has allowed to work with suspensions down to 10 10 L -1 [205].…”

Section: By Using Vip Size and Mass Concentration Of Silver Nanopartmentioning

confidence: 99%

Detection, characterization and quantification of inorganic engineered nanomaterials: A review of techniques and methodological approaches for the analysis of complex samples

Laborda

Bolea

Cepriá

et al. 2016

Analytica Chimica Acta

313

170

View full text Add to dashboard Cite

The increasing demand of analytical information related to inorganic engineered nanomaterials requires the adaptation of existing techniques and methods, or the development of new ones.The challenge for the analytical sciences has been to consider the nanoparticles as a new sort of analytes, involving both chemical (composition, mass and number concentration) and physical information (e.g. size, shape, aggregation). Moreover, information about the species derived from the nanoparticles themselves and their transformations must also be supplied. Whereas techniques commonly used for nanoparticle characterization, such as light scattering techniques, show serious limitations when applied to complex samples, other well-established techniques, like electron microscopy and atomic spectrometry, can provide useful information in most cases. Furthermore, separation techniques, including flow field flow fractionation, capillary electrophoresis and hydrodynamic chromatography, are moving to the nano domain, mostly hyphenated to inductively coupled plasma mass spectrometry as element specific detector.Emerging techniques based on the detection of single nanoparticles by using ICP-MS, but also coulometry, are in their way to gain a position. Chemical sensors selective to nanoparticles are in their early stages, but they are very promising considering their portability and simplicity.Although the field is in continuous evolution, at this moment it is moving from proofs-of-2 concept in simple matrices to methods dealing with matrices of higher complexity and relevant analyte concentrations. To achieve this goal, sample preparation methods are essential to manage such complex situations. Apart from size fractionation methods, matrix digestion, extraction and concentration methods capable of preserving the nature of the nanoparticles are being developed. This review presents and discusses the state-of-the-art analytical techniques and sample preparation methods suitable for dealing with complex samples. Single-and multimethod approaches applied to solve the nanometrological challenges posed by a variety of stakeholders are also presented.

show abstract

Single Nanoparticle Collisions at Microfluidic Microband Electrodes: The Effect of Electrode Material and Mass Transfer

Cited by 42 publications

References 39 publications

Addressing Colloidal Stability for Unambiguous Electroanalysis of Single Nanoparticle Impacts

Addressing Colloidal Stability for Unambiguous Electroanalysis of Single Nanoparticle Impacts

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

Detection, characterization and quantification of inorganic engineered nanomaterials: A review of techniques and methodological approaches for the analysis of complex samples

Contact Info

Product

Resources

About