排序方式: 共有39条查询结果,搜索用时 515 毫秒
1.
2.
Dr. Abdulghani Ismail Dr. Silvia Voci Lucie Descamps Dr. Arnaud Buhot Prof. Dr. Neso Sojic Dr. Loïc Leroy Dr. Aurélie Bouchet-Spinelli 《Chemphyschem》2021,22(11):1094-1100
This work depicts the original combination of electrochemiluminescence (ECL) and bipolar electrochemistry (BPE) to map in real-time the oxidation of silicon in microchannels. We fabricated model silicon-PDMS microfluidic chips, optionally containing a restriction, and monitored the evolution of the surface reactivity using ECL. BPE was used to remotely promote ECL at the silicon surface inside microfluidic channels. The effects of the fluidic design, the applied potential and the resistance of the channel (controlled by the fluidic configuration) on the silicon polarization and oxide formation were investigated. A potential difference down to 6 V was sufficient to induce ECL, which is two orders of magnitude less than in classical BPE configurations. Increasing the resistance of the channel led to an increase in the current passing through the silicon and boosted the intensity of ECL signals. Finally, the possibility of achieving electrochemical reactions at predetermined locations on the microfluidic chip was investigated using a patterning of the silicon oxide surface by etched micrometric squares. This ECL imaging approach opens exciting perspectives for the precise understanding and implementation of electrochemical functionalization on passivating materials. In addition, it may help the development and the design of fully integrated microfluidic biochips paving the way for development of original bioanalytical applications. 相似文献
3.
Remote Actuation of a Light-Emitting Device Based on Magnetic Stirring and Wireless Electrochemistry
Alice L. Dauphin Dr. Stéphane Arbault Prof. Dr. Alexander Kuhn Prof. Dr. Neso Sojic Dr. Laurent Bouffier 《Chemphyschem》2020,21(7):600-604
We propose a straightforward access to a rotating light-emitting device powered by wireless electrochemistry. A magnetic stirrer is used to rotate a light-emitting diode (LED) due to the intrinsic magnetic properties of the tips that contain iron. At the same time, the LED is submitted to an electric field and acts as a bipolar electrode. The electrochemical processes that are coupled on both extremities of the LED drive an electron flow across the device, resulting in light emission. The variation of the LED alignment in time enables an alternating light emission that is directly controlled by the rotation rate. The stirring also enables a continuous mixing of the electrolyte that improves the stability of the output signal. Finally, the LED brightness can readily reveal a change of chemical composition in the electrolyte solution. 相似文献
4.
Milica Sentic Stéphane Arbault Laurent Bouffier Dragan Manojlovic Alexander Kuhn Neso Sojic 《Chemical science》2015,6(8):4433-4437
Among luminescence techniques, electrogenerated chemiluminescence (ECL) provides a unique level of manipulation of the luminescent process by controlling the electrochemical trigger. Despite its attractiveness, ECL is by essence a 2D process where light emission is strictly confined to the electrode surface. To overcome this intrinsic limitation, we added a new spatial dimension to the ECL process by generating 3D ECL at the level of millions of micro-emitters dispersed in solution. Each single object is addressed remotely by bipolar electrochemistry and they generate collectively the luminescence in the bulk. Therefore, the entire volume of the solution produces light. To illustrate the generality of this concept, we extended it to a suspension of multi-walled carbon nanotubes where each one acts as an individual ECL nano-emitter. This approach enables a change of paradigm by switching from a surface-limited process to 3D electrogenerated light emission. 相似文献
5.
Electrogenerated Chemiluminescence of Cationic Triangulene Dyes: Crucial Influence of the Core Heteroatoms 下载免费PDF全文
Dr. Catherine Adam Antoine Wallabregue Haidong Li Jérôme Gouin Dr. Rémi Vanel Stéphane Grass Dr. Johann Bosson Dr. Laurent Bouffier Prof. Jérôme Lacour Prof. Neso Sojic 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(52):19243-19249
Trianguleniums are fascinating conjugated hexacyclic cations that exhibit interesting electronic and optical properties. Herein, the electrogenerated chemiluminescence (ECL) emission of this family of fluorescent dyes is reported for the first time. Redox behavior and fluorescence properties of eight cationic triangulene luminophores with different heteroatom patterns in the core structure and various pending substituents were examined to rationalize the ECL. Clearly, the more electron‐rich the carbocation, the more efficient the corresponding ECL; two very distinct classes of triangulenes can be drawn from these studies by using an ECL wall sufficiency formalism. 相似文献
6.
A high-density array of opto-electrochemical nanosensors is presented for remote DNA detection. It was fabricated by chemical etching of a coherent optical fibre bundle to produce a nanotip array. The surface of the etched bundle was sputter-coated with a thin ITO layer which was eventually insulated by an electrophoretic paint. The fabrication steps produced a high-density array of electrochemical nanosensors which retains the optical fibre bundle architecture and its imaging properties. A DNA probe was then immobilized on the nanosensor array surface in a polypyrrole film by electropolymerisation. After hybridisation with the complementary sequence, detection of the strepavidin-R-phycoerythrin label is performed by fluorescence imaging through the optical fibre bundle itself. Control experiments and regeneration steps have also been successfully demonstrated on this nanostructured opto-electrochemical platform. 相似文献
7.
Sunpet Assavapanumat Thittaya Yutthalekha Patrick Garrigue Bertrand Goudeau Vronique Lapeyre Adeline Perro Neso Sojic Chularat Wattanakit Alexander Kuhn 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(11):3509-3513
Concepts leading to single enantiomers of chiral molecules are of crucial importance for many applications, including pharmacology and biotechnology. Recently, mesoporous metal phases encoded with chiral information have been developed. Fine‐tuning of the enantioaffinity of such structures by imposing an electric potential is proposed, which can influence the electrostatic interactions between the chiral metal and the target enantiomer. This allows the binding affinity between the chiral metal and the target enantiomer to be increased, and thus, the discrimination between two enantiomers to be improved. The concept is illustrated by generating chiral encoded metals in a microfluidic channel by reduction of a platinum salt in the presence of a liquid crystal and l ‐tryptophan as a chiral model template. After removal of the template molecules, the modified microchannel retains a pronounced chiral character. The chiral recognition efficiency of the microchannel can be fine‐tuned by applying a suitable potential to the metal phase. This enables the separation of both components of a racemate flowing through the channel. The approach constitutes a promising and complementary strategy in the frame of chiral discrimination technologies. 相似文献
8.
9.
An array of nanometer-sized apertures capable of electrochemically modulating the fluorescence of a model analyte is presented. The device, which combines near-field optical methods and ultramicroelectrode properties in an array format, is based on an etched coherent optical fiber bundle. Indeed, the fabrication steps produced an ordered array where each optical nanoaperture is surrounded by a ring-shaped gold nanoelectrode. The chronoamperometric behavior of the array shows stable diffusion-limited quasi-steady-state response. The model analyte, tris(2,2'-bipyridine) ruthenium, emits fluorescence in the Ru(II) state, but not in the oxidized Ru(III) state. Fluorescence is excited by visible light exiting from each nanoaperture since light is confined to the tip apex by the gold coating. A fraction of the isotropically emitted luminescence is collected by the same nanoaperture, transmitted by the corresponding fiber core and eventually detected by a charge-coupled device (CCD) camera. The array format provides a fluorescence image resolved at the nanometric scale which covers a large micrometric area. Therefore the high-density array plays a bridging role between these two fundamental scales. We established that the opto-electrochemical nanoapertures are optically independent. Fluorescence of the sample collected by each nanoaperture is modulated by changing the potential of the nanoring electrodes. Reversible electrochemical switching of remote fluorescence imaging is performed through the opto-electrochemical nanoaperture array itself. Eventually this ordered structure of nanometer light sources which are electrochemically manipulated provides promising photonic or electro-optical devices for various future applications. For example, such an array has potential in the development of a combined SNOM-electrochemical nanoprobe array to image a real sample concomitantly at the nanometer and micrometer scale. 相似文献