Wireless Synthesis and Activation of Electrochemiluminescent Thermoresponsive Janus Objects Using Bipolar Electrochemistry

Abstract

In this work, bipolar electrochemistry (BPE) is used as a dual wireless tool to generate and to activate a thermoresponsive electrochemiluminescent (ECL) Janus object. For the first time, BPE allows regioselective growth of a poly(N-isopropylacrylamide) (pNIPAM) hydrogel film on one side of a carbon fiber. It is achieved thanks to the local reduction of persulfate ions, which initiate radical polymerization of NIPAM. By controlling the electric field and the time of the bipolar electrochemical reactions, we are able to control the length and the thickness of the deposit. The resulting pNIPAM film is found to be swollen in water at room temperature and collapsed when heated above 32 °C. We further incorporated a covalently attached ruthenium complex luminophore, Ru(bpy), in the hydrogel film. In the second time, BPE is used to activate remotely the electrogenerated chemiluminescence (ECL) of the Ru(bpy) moieties in the film. We take advantage of the film responsiveness to amplify the ECL signal. Upon collapse of the film, the ECL signal, which is sensitive to the distance between adjacent Ru(bpy) centers, is strongly amplified. It is therefore shown that BPE is a versatile tool to generate highly sophisticated materials based on responsive polymers, which could lead to sensitive sensors.

Buoyant force-induced continuous floating and sinking of Janus micromotors

“…Bipolar electrochemistry, as a powerful technique, has attracted great interest in the fabrication of Janus particles with tunable surface coverage of particles by applying various external voltages on driving electrodes. [22][23][24][25] Conductive particles are placed in the electrolyte solution to serve as bipolar electrodes. When the voltage is sufficiently high, redox reactions can take place at the two faces of all of these conductive particles simultaneously.…”

An Erosion-Corrosion Investigation of Coated Steel for Applications in the Oil and Gas Field, Based on Bipolar Electrochemistry

“…By carefully selecting the experimental parameters, electrochemical reactions at the surface of a conducting object can be accurately controlled [22][23][24]. Recent applications of bipolar electrochemistry focus on sensing, electrografting, electrodissolution, electrodeposition in fields covering chemistry, biology, materials science and device fabrication [24][25][26][27][28].…”

Wireless Coupling of Conducting Polymer Actuators with Light Emission

“…Prominent examples comprise color change, [20,22] site selective deposition, [23][24][25][26][27] exfoliation, [28] motion, [29][30][31][32][33] light emission [34,35] and chemical read out, [18,36,37] etc. Prominent examples comprise color change, [20,22] site selective deposition, [23][24][25][26][27] exfoliation, [28] motion, [29][30][31][32][33] light emission [34,35] and chemical read out, [18,36,37] etc.…”

“…In general, breaking the symmetry based on bipolar electrochemistry in terms of shape, composition or other physicochemical features of conducting and semiconducting objects is already very well known. Prominent examples comprise color change, [20,22] site selective deposition, [23][24][25][26][27] exfoliation, [28] motion, [29][30][31][32][33] light emission [34,35] and chemical read out, [18,36,37] etc. Bipolar electrochemistry has also been reported to drive electronic devices, [38] leading for example to light emitting eswimmers.…”