A graphene oxide/conducting polymer nanocomposite for electrochemical dopamine detection: origin of improved sensitivity and specificity

Abstract

This work describes the performance of a graphene oxide/poly(3,4-ethylenedioxythiophene) nanocomposite material as a sensitive and selective electrochemical dopamine sensor.

Enhanced dopamine detection sensitivity by PEDOT/graphene oxide coating on in vivo carbon fiber electrodes

“…GO was synthesized via the modified Hummer’s method used in previous work (Hummers and Offeman 1958; Luo et al 2013a; Weaver et al 2014a; Weaver et al 2014b) and stored as a concentrated stock in water until use. Prior to use, GO was diluted to 5 mg/mL with water and spiked with 1 μL/mL EDOT monomer.…”

“…Prior to use, GO was diluted to 5 mg/mL with water and spiked with 1 μL/mL EDOT monomer. The EDOT/GO solution was stirred vigorously overnight at 4°C prior to 60 minutes (Weaver et al 2014b) of continuous probe sonication. Probe sonication serves to mechanically exfoliate the GO nanosheets, altering the size and thickness of the GO nanoparticles (Weaver et al 2014a; Weaver et al 2014b), in addition to aiding the dissolution of the EDOT monomer.…”

“…Poly(3,4-ethylene dioxythiophene) (PEDOT) is electro-polymerized from 3,4-ethylene dioxythiophene (EDOT) monomers. The oxidative polymerization of PEDOT results in positive charges on the polymer backbone, this allows for the incorporation of negatively charged doping agents, such as graphene oxide (GO) (Luo et al 2013a; Wang et al 2015; Wang et al 2014; Weaver et al 2014a; Weaver et al 2014b), polystyrene sulfonate (PSS) (Alemu et al 2012; Tait et al 2013), carbon nanotubes (CNT) (Gerwig et al 2012; Luo et al 2011; Xu et al 2013), Nafion (Vreeland et al 2015; Wang and Olbricht 2010) and tosylate (Larsen et al 2012; Vreeland et al 2014), for the purpose of charge balancing. The introduction of a doping agent also has the added benefit of incorporating additional reactive functional groups.…”

“…In particular, PEDOT/GO and its PEDOT/reduced GO counterpart have been shown to be effective for the selective chemical sensing of DA on 3mm diameter glassy carbon macroelectrodes using conventional cyclic voltammetry (100 mV/s sweep rate) (Wang et al 2014; Weaver et al 2014b). In addition, PEDOT/GO coatings can undergo controlled drug delivery upon the application of a trigger potential (Weaver et al 2014a) or be functionalized to promote cellular interactions for tissue engineering applications (Luo et al 2013b).…”

Poly(ionic liquids) functionalized polypyrrole/graphene oxide nanosheets for electrochemical sensor to detect dopamine in the presence of ascorbic acid

“…Recently, novel composite film materials composed of conducting polymers (CPs) and graphene (G) or graphene oxide (GO) have attracted a tremendous amount of attentions and become a research focus, because they possess both excellent properties of conducting polymers and graphene or graphene oxide, such as high electric conductivity at room temperature, long term environmental stability, good electrochemical activity and biocompatibility (Guiseppi-Elie, 2010;Lee et al, 2006) of CPs, as well as unique electrical and chemical properties of G or GO (Kuila et al, 2011;Liu et al, 2012b). Therefore, CPs/G or CPs/GO nanocomposite materials can be applied in many fields such as energy storage, supercapacitors or electrochemical sensors and biosensors for the detection of certain special substances, for instance, polyaniline/grapheme (PANI/G) (Gómez et al, 2011) and polypyrrole/graphene oxide (PPy/GO) (Zhu et al, 2012) exhibited good electrochemical properties and cycling performance, which should be promisingly used for the fabrication of inexpensive, high-performance electrochemical supercapacitors; poly(3,4-ethylenedioxythiophene)/graphene oxide (PEDOT/GO) nanocomposite modified electrode exhibited lowered impedance and increased charge storage capacity as well as improved sensitivity to the oxidation of dopamine (DA) in the presence of ascorbic acid (AA) and uric acid (UA) (Weaver et al, 2014). However, most CPs/G or CPs/GO nanocomposites were prepared by electrochemical deposition (Chang et al, 2012;Si et al, 2011;Zhu et al, 2012) which limited their high-volume production.…”