Schmitt V., Ravaine V.,
Curr. Opin. Colloid Interface Sci. 2013, 18, 532–541. Review

Colloidal gel particles called microgels have shown their ability to adsorb at an oil–water interface and stabilise emulsion named Pickering emulsions. Such particles are soft, deformable, and porous, and they can swell or contract under the action of an external stimulus. These specificities make them emulsifiers of special interest as they offer a large versatility to emulsions and materials elaborated thereof. This modularity is in counterpart at the origin of an abundant and often contradictory literature. The aim of this paper is to review recent advances in the emulsion stabilisation mechanism, particularly focusing on the microgel conformation at the interface in relation with the mechanical interface behaviour and the emulsion macroscopic stability. A sum up of the unambiguous knowledge is also proposed as well as few central questions that remain to be answered to in the domain.

 

CurrOpCollInterSci2013 p532 TOC

Husken N., Taylor R. W., Zigah D., Taveau J.-C., Lambert O., Scherman O. A., Baumberg J. J., Kuhn A.,
Nano Lett. 2013, 13, 6016–6022.

One-dimensional (1D) nanoparticle chains with defined nanojunctions are of strong interest due to their plasmonic and electronic properties. A strategy is presented for the assembly of 1D gold-nanoparticle chains with fixed and rigid cucurbit[n]uril-nanojunctions of 9 Å. The process is electrokinetically accomplished using a nanoporous polycarbonate membrane and controlled by the applied voltage, the nanoparticle/CB[n] concentration ratio, time and temperature. The spatial structure and time-resolved analysis of chain plasmonics confirm a growth mechanism at the membrane nanopores.

 

NanoLett2013 p6016 TOC

Destribats M., Wolfs M., Pinaud F., Lapeyre V., Sellier E., Schmitt V., Ravaine V.,
Langmuir 2013, 29, 12367–12374.

This work reports a new evidence of the versatility of soft responsive microgels as stabilizers for Pickering emulsions. The organization of microgels at the oil–water interface is a function of the preparation pathway. The present results show that emulsification energy can be used as a trigger to modify microgel deformation at the oil–water interface and their packing density: high shear rates bring strong flattening of the microgels, whereas low shear rates lead to dense monolayers, where the microgels are laterally compressed. As a consequence, the resulting emulsions have opposite behavior in terms of flocculation, which arises from bridging between neighboring drops and is strongly dependent on their surface coverage. This strategy can be applied to any microgel which can sufficiently adsorb at low shear rates, i.e. small microgels or lightly cross-linked ones. The control of the organization of microgels at the interface does not only modify emulsion end-use properties but also constitutes a new tool for the development of Janus-type microgels, obtained by chemical modification of the adsorbed microgels.

 

Langmuir2013 p12367 TOC

Chen K., Adam C., Sojic N., Schmittel M.,
RSC Adv. 2013, 33, 24140–24145.

For remote Hg2+ detection, an array of nanotips was covalently functionalised using a versatile photochemical approach. After chemical etching of an optical fiber bundle to generate the nanotip array, a protected n-propyl amine was grafted onto the tip surface by silanisation and thereafter photodeprotected by irradiation at 365 nm. The new rhodamine-based probe 9 developed for detection of Hg2+ was linked to the liberated amino group using the HOBt/DCC protocol. The optical fiber bundles functionalised with 9 exhibited a high selectivity toward Hg2+in situ, in full analogy to its precursor 4 in solution. Titration of the functionalised optical fiber bundles using a remote detection mode showed a detection range from 10−5 to 5 × 10−3 M for mercury ions in aqueous medium.

 

RSCAdv2013 p24140 TOC

Suraniti E., Kanoufi F., Gosse C., Zhao X., Dimova R., Pouligny B., Sojic N.,
Anal. Chem. 2013, 85, 8902–8909. Editors' Highlight !

Latex micrometric beads are manipulated by optical tweezers in the vicinity of an ultramicroelectrode (UME). They are optically trapped in solution and approached the electrode surface. After the electrochemical measurement, they are optically removed from the surface. The residence time of the particle on the electrode is thus controlled by the optical tweezers. The detection is based on diffusional hindrance by the insulating objects which alters the fluxes of the redox Ru(NH3)63+ species toward the UME and thus its mass-transfer limited current. We have optically deposited successively 1, 2, and 3 beads of 3-μm radius on the UME surface, and we have recorded the variations of the current depending on their landing locations that were optically controlled. Finally we decreased the current by partially blocking the electroactive surface with a six-bead assembly. The variation of the steady-state current and the approach curves allow for the indirect electrochemical localization of the bead in the vicinity of the UME, not only when the bead is in contact but also when it is levitated at distances lower than the UME radius. These experiments show that single particles or more complex structures may be manipulated in situ in a contactless mode near the UME surface. From comparison with simulations, the electrochemical detection affords an indirect localization of the object in the UME environment. The developed approach offers a potential application for interrogating the electrochemical activity of single cells and nanoparticles.

 

AnalChem2013 p8902 TOC

Surface Compaction Versus Stretching in Pickering Emulsions Stabilised by Microgels
Thursday, 07 November 2013
Schmitt V., Ravaine V.,Curr. Opin. Colloid Interface Sci. 2013, 18, 532–541. Review Colloidal gel particles called microgels have shown their ability to adsorb at an oil–water interface and...
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Electrokinetic Assembly of One-Dimensional Nanoparticle Chains with Cucurbit[7]uril Controlled Subnanometer Junctions
Friday, 01 November 2013
Husken N., Taylor R. W., Zigah D., Taveau J.-C., Lambert O., Scherman O. A., Baumberg J. J., Kuhn A.,Nano Lett. 2013, 13, 6016–6022. One-dimensional (1D) nanoparticle chains with defined...
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Photochemical Functionalisation of Optical Nanotips with a Rhodamine Chemosensor for Remote Through-Fiber Detection of Hg2+
Monday, 21 October 2013
Chen K., Adam C., Sojic N., Schmittel M.,RSC Adv. 2013, 33, 24140–24145. For remote Hg2+ detection, an array of nanotips was covalently functionalised using a versatile photochemical approach....
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Pickering Emulsions Stabilized by Soft Microgels: Influence of the Emulsification Process on Particle Interfacial Organization and Emulsion Properties
Thursday, 19 September 2013
Destribats M., Wolfs M., Pinaud F., Lapeyre V., Sellier E., Schmitt V., Ravaine V.,Langmuir 2013, 29, 12367–12374. This work reports a new evidence of the versatility of soft responsive microgels...
Read More...
Electrochemical Detection of Single Microbeads Manipulated by Optical Tweezers in the Vicinity of Ultramicroelectrodes
Tuesday, 10 September 2013
Suraniti E., Kanoufi F., Gosse C., Zhao X., Dimova R., Pouligny B., Sojic N.,Anal. Chem. 2013, 85, 8902–8909. Editors' Highlight ! Latex micrometric beads are manipulated by optical tweezers in the...
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Comprehensive Study of DNA Binding on Iron(II,III) Oxide Nanoparticles with a Positively Charged Polyamine Three-Dimensional Coating
Tuesday, 13 August 2013
Yiu H. H. P., Bouffier L., Boldrin P., Long J., Claridge J. B., Rosseinsky M. J.,Langmuir 2013, 29, 11354-11365. Iron (II,III) oxide Fe3O4 nanoparticles (25 and 50 nm NPs) are grafted with amine...
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Capillary Electrophoresis as a Production Tool for Asymmetric Microhybrids
Wednesday, 17 July 2013
Fattah Z., Garrigue P., Goudeau B., Lapeyre V., Kuhn A., Bouffier L.,Electrophoresis 2013, 34, 1985-1990. The site selective electrodeposition of silver metal onto a conducting object such as carbon...
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Development of Electrochemical Microsensors for the Monitoring of Mitochondrial Activities
Tuesday, 18 June 2013
Vanhove E., Ben-Amor S., Charlot S., Colin D., Devin A., Rigoulet M., Sojic N., Sékli Belaïdi F., Launay J., Temple-Boyer P., Arbault S.,I.E.E.E., Proceedings of Transducers 2013, 1135-1138....
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Bipolar Electrochemistry: From Materials Science to Motion and Beyond
Wednesday, 29 May 2013
Loget G., Zigah D., Bouffier L., Sojic N., Kuhn A.Acc. Chem. Res. 2013, 46, 2513-2523. Bipolar electrochemistry, a phenomenon which generates an asymmetric reactivity onthe surface of conductive...
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Electrochemiluminescent Polymer Film with suitable Redox “turn-off” Absorbance window for Remote Selective Sensing of Hg2+
Thursday, 16 May 2013
Shu Q., Adam C., Sojic N., Schmittel M.,Analyst 2013, 138, 4500-4504. An electrochemiluminescent sensing scheme is presented for remote detection of Hg2+ through an ITO-coated nanostructured optical...
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Photochemical Crosslinking of Hyaluronic Acid confined in Nanoemulsions: towards Nanogels with a Controlled Structure
Tuesday, 07 May 2013
Messager L., Portecop N., Hachet E., Lapeyre V., Pignot-Paintrand I., Catargi B., Auzély-Velty R., Ravaine V.,J. Mater. Chem. B 2013, 1, 3369-3379. We present the preparation of nanogels made of...
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Monitoring Metabolic Responses of Single Mitochondria within PDMS Wells: Study of their Endogenous NADH Evolution
Friday, 19 April 2013
Suraniti E., Vajrala S. R., Goudeau B., Bottari S., Rigoulet M., Devin A., Sojic N., Arbault S.,Anal. Chem. 2013, 85, 5146-5152. It is now demonstrated that mitochondria individually function...
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Functionalization of Optical Nanotip Arrays with an Electrochemical Microcantilever for Multiplexed DNA Detection
Friday, 12 April 2013
Descamps E., Duroure N., Deiss F., Leichlé T., Adam C., Mailley P., Aït-Ikhlef A., Livache T., Nicu L., Sojic N.,Lab on a Chip 2013, 13, 2956-2962. Optical nanotip arrays fabricated on etched fiber...
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Enhanced Electrogenerated Chemiluminescence in Thermo-Responsive Microgels
Friday, 29 March 2013
Pinaud F., Russo L., Pinet S., Gosse I., Ravaine V., Sojic N.,J. Am. Chem. Soc. 2013, 135, 5517-5520. The electrochemistry, photoluminescence and electrogenerated chemiluminescence of...
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Chemiluminescence from Asymmetric Inorganic Surface Layers generated by Bipolar Electrochemistry
Thursday, 07 March 2013
Fattah Z., Roche J., Garrigue P., Zigah D., Bouffier L., Kuhn A.,Chem. Phys. Chem. 2013, 14, 2089-2093. Blue light on a Janus rod: Prussian Blue (PB) is locally generated in an asymmetric way on a...
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Introducing a well-ordered Volume Porosity in 3-Dimensional Gold Microcantilevers
Monday, 04 February 2013
Ayela C., Lalo H., Kuhn A.,Appl. Phys.Lett. 2013, 102, 053501. The purpose of the present work is the introduction of a combined bottom-up and top-down approach to generate 3-dimensional gold...
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Enhanced Hydrogen Peroxide Sensing based on Prussian Blue modified Macroporous Microelectrodes
Sunday, 27 January 2013
Mokrushina A. V., Heim M., Karyakina E. E., Kuhn A., Karyakin A. A.,Electrochem. Comm. 2013, 29, 78-80. We report on the successful modification of macroporous microelectrodes with the...
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Oxygen Plasma Treatment Of Platinized Ultramicroelectrodes Increases Sensitivity For Hydrogen Peroxide Detection On Mitochondria
Thursday, 24 January 2013
Ben-Amor S., Devin A., Rigoulet M., Sojic N., Arbault S., Electroanalysis 2013, 25, 656-663. Hydrogen peroxide is a major bio-active molecule produced by mitochondria during aerobic metabolism. In...
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Wireless Electrografting of Molecular Layers for Janus Particle Synthesis
Friday, 28 December 2012
Kumsapaya C., Bakai M.-F., Loget G., Goudeau B., Warakulwit C., Limtrakul J., Kuhn A., Zigah D.,Chemistry - A European Journal 2013, 19, 1577-1580. Glassy carbon beads are selectively functionalized...
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Hierarchical Macro-mesoporous Pt Deposits on Gold Microwires for Efficient Methanol Oxidation
Monday, 05 November 2012
Heim M., Wattanakit C., Reculusa S., Warakulwit C., Limtrakul J., Ravaine S., Kuhn A.,Electroanalysis 2013, 25, 888-894. Hierarchically ordered macro-mesoporous Pt films have been synthesized on gold...
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Design of a Wireless Electrochemical Valve
Thursday, 01 November 2012
Bouffier L., Kuhn A., Nanoscale 2013, 5, 1305-1309. The control of motion of small objects is an emerging research area. Their design strongly depends on the strategy chosen to trigger the...
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Effect of Novel Antibacterial Gallium-Carboxymethyl Cellulose on Pseudomonas Aeruginosa
Tuesday, 30 October 2012
Valappil S. P., Yiu H. H. P., Bouffier L., Hope C. K., Evans G., Claridge J. B., Higham S. M., Rosseinsky M. J., Dalton Trans. 2013, 42, 1778-1786. Gallium has emerged as a new therapeutic agent due...
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Interest of the Sol-Gel Approach for Multiscale Tailoring of Porous Bioelectrode Surfaces
Friday, 26 October 2012
Bon Saint Côme Y., Lalo H., Wang Z., Kohring G.W, Hempelmann R., Etienne M., Walcarius A., Kuhn A., Electroanalysis 2013, 25, 621-629. Gold nanoparticles have been co-encapsulated with d-sorbitol...
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