J. Kalecki, M. Cieplak, M. Dąbrowski, W. Lisowski, A. Kuhn,  P. Sindhu Sharma

ACS Sensors (2019) in press, doi.org/10.1021/acssensors.9b01878

Homogenous nanostructuration of molecularly imprinted polymer (MIP) films for follicle-stimulating hormone (FSH) sensing was achieved by using optimized colloidal crystals as a hard mold. Introduction of heating step after assembling colloidal crystals of silica beads promoted their adhesion.  Thus precise assembling of beads was not disturbed during further multistep of surface imprinting, and crack free hexagonal packing was maintained.  SEM imaging confirmed hexagonal packing of silica colloidal crystals as well as homogenous nanostructurization in MIP films. FSH immobilization over silica beads and later its derivatization with electroactive functional monomers was confirmed by XPS analysis. The nanostructured molecular recognition films prepared in this way were combined with an electrochemical transducer in order to design a capacitive impedimetry (CI) based chemosensing system. It was tested for the determination of FSH in the range from 0.1 fM to 100 pM in 10 mM MES buffer (pH = 4.2).  The detection limit of the chemosensor was 0.1 fM showing a high selectivity with respect to common protein interferences as well as other protein hormones of the gonadotropin family.

2019 21

 

C. Wattanakit, A. Kuhn

Chemistry-A European Journal (2020) 26, 2993-3003

The concept of encoding molecular information in bulk metals has been proposed over the past decade. The structure of various types of molecules has been imprinted, including also enantiomers. Typically, to encode metals with chiral information, several approaches, based on chemical and electrochemical concepts, can be used. In this minireview we discuss recent achievements with respect to the development of such materials, including the entrapment of chiral biomolecules in metals, the chiral imprinting of metals, as well as the combination of imprinting with nanostructuring. The features and potential applications of these designer materials, such as chirooptical properties, enantioselective adsorption and separation as well as their use for asymmetric synthesis will be presented. This will illustrate that the development of molecularly encoded metal structures opens up very interesting perspectives, especially in the frame of chiral technologies.

2019 19

T. Bombail, P. Garrigue, B. Goudeau, D. Talaga, L. Bouffier, S. Bonhommeau, L. Servant, D. Zigah, S. Arbault, N. Sojic

Electrochim. Acta, 2019, DOI: 10.1016/j.electacta.2019.135105.

Gold microelectrodes decorated with nanotips were developed for spectroelectrochemical experiments. These new dual probes were fabricated by combining fabrication processes of scanning near-field optical microscopy with photolithography. A nanotip array was produced at the surface of a coherent optical fiber bundle by a wet chemical etching step. The resulting nanostructured surface was sputter-coated with a thin gold layer. This gold film conferred plasmonic properties to the sharp nanotips and served as well as the electrode material to enable electrochemical reactions. A photolithographic process was used to define on the bundle surface nanotips-decorated microelectrodes with tunable dimensions (radii ranging between 20 μm and 3.5 μm) individually or in an array format. The resulting microelectrodes with a regular nanotip pattern were characterized first by cyclic voltammetry. Numerical simulation was used to assess the electrochemical properties of these platforms and the influences of the recessed geometry and of the nanotips. Approach curves were recorded in negative and positive feedback modes of scanning electrochemical microscopy (SECM) on insulating and conducting substrates. Finally, spatially resolved Raman imaging allowed us to detect a mercaptobenzoic acid monolayer adsorbed on the microelectrode surface, demonstrating a surface-enhanced Raman scattering (SERS) effect induced by the gold-coated nanotips with a typical enhancement factor of ∼7 × 104. Such an approach introduces a reproducible method to fabricate promising SERS-active platforms with microelectrode behavior for SECM experiments.

tips

S. Assavapanumat,  M. Ketkaew,  A. Kuhn, C.Wattanakit

J. Am.Chem.Soc. 141 (2019) 18870 (Front Cover)

see also CNRS press release

The enantioselective synthesis of chiral compounds is of crucial importance for a wide range of potential applications, especially in cosmetic and pharmaceutical industries. Recently, chiral imprinted mesoporous platinum films, produced by the electrodeposition of the metal, in the simultaneous presence of a lyotropic liquid crystalline phase of non-ionic surfactants as mesoporogens and chiral templates, have been applied as electrocatalysts and selective stationary phases for the asymmetric synthesis and separation of chiral compounds, respectively. However, platinum is an expensive metal and therefore it is mandatory to explore the possibility to apply this concept also to other metals. In this contribution, we propose mesoporous chiral imprinted nickel as an alternative cheap and earth-abundant metal. The designed surface layers not only demonstrate electrochemical discrimination between two enantiomers, but most importantly, also allow stereospecific electroreduction of a prochiral compound, with very significant enantioselectivity of up to 80% ee. These results open up very promising perspectives for the development of low cost non-noble metal matrices for the synthesis of chiral compounds.

2019 20

A. Bouchet-Spinelli, E. Descamps, J. Liu, A. Ismail, P. Pham, F. Chatelain, T. Leïchlé, L. Leroy, P. N. Marche, C. Raillon, A. Roget, Y. Roupioz, N. Sojic, A. Buhot, V. Haguet, T. Livache and P. Mailley

Biosensors 2019, 9, 121; doi:10.3390/bios9040121

This review summarizes recent advances in micro- and nanopore technologies with a focus on the functionalization of pores using a promising method named contactless electro-functionalization (CLEF). CLEF enables the localized grafting of electroactive entities onto the inner wall of a micro- or nano-sized pore in a solid-state silicon/silicon oxide membrane. A voltage or electrical current applied across the pore induces the surface functionalization by electroactive entities exclusively on the inside pore wall, which is a significant improvement over existing methods. CLEF’s mechanism is based on the polarization of a sandwich-like silicon/silicon oxide membrane, creating electronic pathways between the core silicon and the electrolyte. Correlation between numerical simulations and experiments have validated this hypothesis. CLEF-induced micro- and nanopores functionalized with antibodies or oligonucleotides were successfully used for the detection and identification of cells and are promising sensitive biosensors. This technology could soon be successfully applied to planar configurations of pores, such as restrictions in microfluidic channels.

micropore

Thumbnail Dezest M., Bulteau A.L., Quinton D., Chavatte L., Le Béchec M., Arbault S., Salvayre A.N., Cousty S., Clément F. PLOS One, 2017, 12(3) Cold atmospheric pressure plasmas (CAPPs) are known to have...
Thumbnail C. Wattanakit, T. Yutthalekha, S. Asssavapanumat, V. Lapeyre, A. Kuhn Nature Comm. 2017, 8, 2087 see also CNRS press release Asymmetric synthesis of molecules is of crucial importance to obtain...
Thumbnail Giovanni Valenti, Sabina Scarabino, Bertrand Goudeau, Andreas Lesch, Milica Jovic, Elena Villani, Milica Sentic, Stefania Rapino, Stephane Arbault, Francesco Paolucci, and Neso Sojic J. Am. Chem....
Thumbnail V. Eßmann, S. Voci, G. Loget, N. Sojic, W. Schuhmann, A. Kuhn J. Phys. Chem. Lett. 2017,8, 4930–4934   Bipolar electrochemistry has been shown to enable and control various kinds of propulsion of...
Thumbnail Guangnan Meng, Vinothan N. Manoharan and Adeline Perro Soft Matter, 2017,13, 6293-6296 We design polystyrene–poly(N′-isopropylacrylamide-co-acrylic acid) core–shell particles that exhibit...
Thumbnail J. Gao, S. Chen, F. AlTal, S. Hu, L. Bouffier, G. Wantz.  ACS Appl. Mater. Interfaces, 2017, 9, 32405–32410.  A linear array of aluminum discs is deposited between the driving electrodes of an...
Thumbnail B. Gupta, B. Goudeau, A. Kuhn Angew.Chem. Int. Ed. 2017, 56, 14183-14186 see also Highlight in Chemistry Views and CNRS press release Electrochemical actuation of conducting polymers usually...
Thumbnail Z. Ali Fattah, L. Bouffier, A. Kuhn Applied Materials Today 2017, 9, 259–265, COVER Self-propelled micro/nanoswimmers performing directional motion are of great potential nowadays in the frame of...
Thumbnail T.D. Le, D. Lasseux, X.P. Nguyen, G. Vignoles, N. Mano, A. Kuhn Chemical Engineering Science 2017, 173, 153–167 A multi-scale model of diffusion/reaction at play in a porous electrode is developed...
Thumbnail M. Dabrowski, M. Cieplak, K. Noworyta, M. Heim, W. Adamkiewicz, A. Kuhn, P. S. Sharma, W. Kutner J. Mater. Chem. B, 2017,5, 6292-6299 Molecular imprinting in polymers leads, among others, to...
Thumbnail L. Bouffier, T. Doneux.  Current Opinion in Electrochemistry, DOI: 10.1016/j.coelec.2017.06.015. Electrochemistry and fluorescence microscopy are two complementary transduction techniques that offer synergetic...
Thumbnail G. Di Martino,V. A. Turek,  A. Lombardi, I.  Szabó, B. de Nijs,  A. Kuhn, E. Rosta, J.J. Baumberg Nano Lett. 2017, 17, 4840-4845 We study in real time the optical response of individual plasmonic...
Thumbnail Rémy Bois, Sabina Scarabino, Valérie Ravaine, Neso Sojic Langmuir, 2017, DOI: 10.1021/acs.langmuir.7b01585 We describe a method to confine electrochemiluminescence (ECL) at the oil-water interface of emulsion...
Thumbnail D. Zigah, O. Fontaine World Scientific, 2017, ISBN: 978-1-78634-353-6   Bioelectrochemical Systems (BESs) are innovative and sustainable devices. They combine biological and electrochemical...
Thumbnail C. Bodin,  E. Mourad,  D. Zigah,  S. Le Vot,  S. A Freunberger,  F. Favier, O. Fontaine Faraday Discuss., 2017,DOI: 10.1039/C7FD00174F   Nowadays, commercial supercapacitors are based on purely...
Thumbnail S. Tiewcharoen, C. Warakulwit, V. Lapeyre, P. Garrigue, L. Fourier, C. Elissalde, S. Buffière, P. Legros, M. Gayot, J. Limtrakul, A. Kuhn Angew.Chem.Int.Ed. (2017) 56, 11431-11435, COVER, HOT...
Thumbnail G. Di Martino, V. A. Turek,  C. Tserkezis, A. Lombardi, A. Kuhn, J.J. Baumberg Faraday Discuss., 2017, in press,doi 10.1039/C7FD00130D We study the optical response of individual nm-wide plasmonic...
Thumbnail A. G. Mark, E. Suraniti, J. Roche, H. Richter, A. Kuhn, N. Mano, P. Fischer Lab Chip, 2017, 17, 1761 HOT PAPER see also CNRS press release A variety of diagnostic and therapeutic medical...
Thumbnail I. Malytska, C. Mézière, M. Keilar, L. Hirsch, G. Wantz, N. Avarvari, A. Kuhn, L. Bouffier. Journal of Physical Chemistry C 2017, 121, 12921-12927.   Bipolar electrochemistry has recently emerged as a very...
Thumbnail L. Bouffier, S. Reculusa, V. Ravaine, A. Kuhn. ChemPhysChem 2017, 18, 2637-2642.   A new simple and versatile method for the preparation of surface wetting gradients is proposed. It is based on the...
Thumbnail C.A. Busatto, H. Labie, V. Lapeyre, R. Auzely-Velty, A. Perro, N. Casis, J. Luna, D.A. Estenoz, V. Ravaine Journal of Colloid and Interface Science, 493, 2017, 356–364. Polymer microgels have received...
Thumbnail L. Bouffier, N. Sojic, A. Kuhn Electrophoresis, 2017, 38, 2687-2694. A bipolar electrode is quite unconventional as it behaves simultaneously as an anode and a cathode in contrast to a classic...
Thumbnail M. Dabrowski, M. Cieplaka, P. Sindhu Sharma, P. Borowicz, K. Noworyta, W. Lisowski, F. D'Souza, A. Kuhn, W. Kutner Biosens.&Bioelectron.2017, 94, 155-161 Nanostructured artificial receptor...
Thumbnail Nenad R. Filipovic, Hana Elshaflu, Sonja Grubic, Ljiljana S. Jovanovic, Marko Rodic, Irena Novakovic, Aleksandar Malecevic, Ivana S. Djordjevic, Haidong Li, Neso Sojic, Aleksandar Marinkovic,...
Thumbnail Haidong Li, Silvia Voci, Antoine Wallabregue, Catherine Adam, Geraldine M. Labrador, Romain Duwald, Irene Hernández Delgado, Simon Pascal, Johann Bosson, Jérôme Lacour, Laurent BouffierNeso...