Increasing Applications of Graphite Thermoplastic Electrodes with Aryl Diazonium Grafting

Abstract

Carbon composite thermoplastic electrodes (TPEs) consist of graphite and thermoplastic made using an easy, solvent‐assisted fabrication. TPEs have the advantages of high conductivity, good electron transfer kinetics, low cost, reusability, and easy patterning, but have only been used with aqueous solvents due to solvent compatibility with the poly(methyl methacrylate) (PMMA) template. The limited solvent compatibility hinders the application range and surface modifications. Here, cyclic olefin copolymer (COC) TPEs in glass templates that are compatible with additional solvents are presented. TPEs are grafted with aryl diazonium salts in acetonitrile, showing covalent surface TPE modification for the first time. Further investigation is carried out with scanning electrochemical microscopy (SECM). The TPEs are post‐functionalized with a ferrocene moiety via click chemistry. The diazonium electrografting and click chemistry modifications open up future studies and broader applications of TPEs.

A post-functionalization toolbox for diazonium (electro)-grafted surfaces: review of the coupling methods

“…114,129,136,141,156 In these studies, ferrocene, which gives a reversible and stable redox signal, is commercially available, inexpensive and easily chemically functionalizable, was chosen as model molecule. These reasons also motivated the use of this redox probe to validate and better understand different concepts including functionalization of non-conventional electrodes, 132,135,140,157,158 electron transfer, 125,127,128,159 formation of more or less compact monolayers, 105,115,123,124,130,137,139 fabrication of mixed (mono)layers, 105,116,120,122,138 surface structuring, 117,126,131,133 building of dendrimer modified surfaces. 119 Immobilization of this molecule on a reactive platform is also a good way to compare the effectiveness of different functionalization methods.…”

“…Whether they are carried out in one direction or another (azide surface and alkyne in solution, or the opposite), the couplings are made under similar operating conditions. Cupper(I) is always used as a reaction catalyst (directly added, 134,148,162,173,175 or formed in situ from cupper(II) and a reducing agent 85,105,[113][114][115]119,[121][122][123][124]127,128,132,135,139,140,142,147,149,157,158,160,[163][164][165][166]168,177,178 or electrochemically generated 137,176 ). The most common option relies on the combined use of copper(II) sulfate and ascorbic acid (or sodium ascorbate, usually in excess) as reducing agent.…”

“…The left columns allow to target the entity to be grafted and the various reactions identified to immobilize these structures. The reactive platforms are drawn 105,115,116,119,[121][122][123][124][125]127,128,134,139,184 graphene, 132 carbon fibers, 157,158 amorphous carbon nitride, 135 BDD, 137 graphite thermoplastic, 140 MWCNT 141 Anion sensing 119 Electronic junctions 127 Catalytic switches 134 Carbon 156 Biological catalysts 156 Post-diazotization GC, 191,196 gold, 191,196 Fluorescent dyes 150 Nitrobenzene Amide coupling Carbon 88,323 Microcontact printing 88 Trace analysis of copper 323 CNT, 102 gold 324 -Click chemistry GC 138 -…”

Nanofabrication Techniques in Large-Area Molecular Electronic Devices

“…Likewise, materials, such as carbon nanodots (CD) have been immobilized onto carbon substrates, through the attachment of nitrogen moieties at the nanodot surface (diazotized N-CD), resulting in carbon substrates with new performances in sensing applications [330]. Finally, other conductive substrates such as carbon composite electrodes, including thermoplastic electrodes (TPE) [331], edge plane pyrolytic graphite electrodes (PGEs) [332], glassy carbon (GC), and pyrolyzed photoresist (PPF) [333], have also been modified by electrografting.…”

Diazonyum Tuzu Kullanılarak Elektrokimyasal Olarak Modifiye Edilmiş Karbon Kompozit Elektrot

“…TPE literatürde belirtilen şekilde hazırlanmıştır (Berg, Leroux, Hapiot, & Henry, 2019;Klunder et al, 2017). Buna göre, grafit kütlece 1:3 oranında plastik (PCL/PMMA): karbon (kütlece %75 karbon) eklenerek 15 mL metilen klorit içerisinde çözülmüştür.…”