Polyelectrolyte-functionalized ionic liquid for electrochemistry in supporting electrolyte-free aqueous solutions and application in amperometric flow injection analysis

Abstract

As a green process, electrochemistry in aqueous solution without a supporting electrolyte has been described based on a simple polyelectrolyte-functionalized ionic liquid (PFIL)-modified electrode. The studied PFIL material combines features of ionic liquids and traditional polyelectrolytes. The ionic liquid part provides a high ionic conductivity and affinity to many different compounds. The polyelectrolyte part has a good stability in aqueous solution and a capability of being immobilized on different substrates. The electrochemical properties of such a PFIL-modified electrode assembly in a supporting electrolyte-free solution have been investigated by using an electrically neutral electroactive species, hydroquinone (HQ) as the model compound. The partition coefficient and diffusion coefficient of HQ in the PFIL film were calculated to be 0.346 and 4.74 6 10 26 cm 2 s 21 , respectively. Electrochemistry in PFIL is similar to electrochemistry in a solution of traditional supporting electrolytes, except that the electrochemical reaction takes place in a thin film on the surface of the electrode. PFILs are easily immobilized on solid substrates, are inexpensive and electrochemically stable. A PFIL-modified electrode assembly is successfully used in the flow analysis of HQ by amperometric detection in solution without a supporting electrolyte. The results indicate a green electrochemical methodology in supporting electrolyte-free solution and a potential application in amperometric detection in a flow system without any supporting electrolyte in the solution, such as the high performance liquid chromatography electrochemical detection (HPLC-ECD) system.

Application of Room Temperature Ionic Liquids in Electrochemical Sensors and Biosensors

“…(Villagran et al, 2004). In another report a carbon paste base ILs was used in a flow-injection system with a voltammetric detector (Shen et al 2007). The electroactive compounds to be determined can diffuse better from the eluent into the thin layer of the ionic liquid on the surface of a carbon paste electrode as a working electrode.…”

Enhanced response induced by polyelectrolyte-functionalized ionic liquid in glucose biosensor based on sol–gel organic–inorganic hybrid material

“…The IL unit in the PFIL improved the charge transportation in the film matrix and exhibited direct electrocatalysis towards the oxidation of NADH [37]. Furthermore, PFIL could also be used as a film to enhance the electrochemical response in the solutions without addition of supporting electrolytes [38,39]. This method provided an economical way to immobilize ILs on solid supports and indicated a potential application in electroanalytical chemistry.…”

Properties of Poly(sodium 4‐styrenesulfonate)‐Ionic Liquid Composite Film and Its Application in the Determination of Trace Metals Combined with Bismuth Film Electrode

“…In addition, ILs have high ionic conductivity and allow electrochemical studies to be undertaken without additional supporting electrolyte, which can simplify the electrochemical procedure and reduce the expense in electroanalytical measurements [16,17]. Therefore, ILs offers a great opportunity for electrodeposition, nanotechnology and electrochemistry [18,19].…”