Redox‐Stability of Alkoxy‐BDT Copolymers and their Use for Organic Bioelectronic Devices

Giovannitti, Alexander; Thorley, Karl J.; Nielsen, Christian B.; Li, Jun; Donahue, Mary J.; Malliaras, George G.; Rivnay, Jonathan; McCulloch, Iain

doi:10.1002/adfm.201706325

Cited by 85 publications

(130 citation statements)

References 34 publications

Supporting

Mentioning

122

Contrasting

Order By: Relevance

“…[ 8,30 ] It is also applicable to identify degradation processes during electrochemical charging/discharging of OMIECs, where irreversible changes of the absorption spectrum can be related to chemical degradation. [ 18 ] As shown in Figure 2c, the ground state absorption peak of p(gPyDPP‐MeOT2) decreases upon oxidation of the copolymer while a new absorption peak appears for the hole polaron with a similar absorption spectrum as was previously reported for oxidized DPP copolymer analogs. [ 31,32 ] Electrochemically reversible polaron formation up to 0.7 V versus Ag/AgCl is observed for p(gPyDPP‐MeOT2).…”

Section: Figuresupporting

confidence: 67%

“…The products of such side‐reactions may modify the chemical composition of the OMIEC and affect the performance of electrochemical devices. [ 18 ] So far, little attention has been paid to noncapacitive faradaic reactions in ambient, oxygen‐containing aqueous electrolytes. One example of a noncapacitive faradaic reaction is the electron‐transfer reaction from the OMIEC to molecular oxygen, also described as the oxygen reduction reaction (ORR).…”

Section: Figurementioning

confidence: 99%

“…The MeOT2‐unit provides more localization of the wavefunction for the hole polaron than the T2‐unit, and is therefore expected to stabilize the hole polaron further and thus increase the redox stability of the copolymer, as we have previously shown for other donor–acceptor copolymers. [ 18 ] Additionally, the substitution of the hydrogen atoms in the 3‐ and 3′‐positions of the T2 unit to methoxy‐groups (MeOT2 unit) can further shield the backbone from unintended reactions during electrochemical charging (polaron and bipolaron formation).…”

Section: Figurementioning

confidence: 99%

See 2 more Smart Citations

Energetic Control of Redox‐Active Polymers toward Safe Organic Bioelectronic Materials

et al. 2020

Self Cite

View full text Add to dashboard Cite

Organic semiconductors with polar sidechains have been identified as a promising class of materials for the field of bioelectronics. These materials, also called organic mixed ionic/electronic conductors (OMIECs), can exchange ions with aqueous electrolytes when electronic charge carriers are injected, transported, and stored in the bulk of the material. [1] Recent developments of OMIECs based on redox-active conjugated polymers [2][3][4][5][6][7][8] and novel device concepts [9,10] have opened up new pathways for bioelectronic devices including integrated circuits for electroencephalogram (EEG) monitoring [9] or low-power voltage amplifiers based on organic electrochemical transistors (OECTs). [11] Specifically, the OECT has drawn significant attention in the field of organic bioelectronics. It operates by electrochemically modulating the conductivity of a redox-active channel material with an electrolyte that is often aqueous, Avoiding faradaic side reactions during the operation of electrochemical devices is important to enhance the device stability, to achieve low power consumption, and to prevent the formation of reactive side-products. This is particularly important for bioelectronic devices, which are designed to operate in biological systems. While redox-active materials based on conducting and semiconducting polymers represent an exciting class of materials for bioelectronic devices, they are susceptible to electrochemical side-reactions with molecular oxygen during device operation. Here, electrochemical side reactions with molecular oxygen are shown to occur during organic electrochemical transistor (OECT) operation using high-performance, state-of-the-art OECT materials. Depending on the choice of the active material, such reactions yield hydrogen peroxide (H 2 O 2 ), a reactive side-product, which may be harmful to the local biological environment and may also accelerate device degradation. A design strategy is reported for the development of redox-active organic semiconductors based on donor-acceptor copolymers that prevents the formation of H 2 O 2 during device operation. This study elucidates the previously overlooked side-reactions between redox-active conjugated polymers and molecular oxygen in electrochemical devices for bioelectronics, which is critical for the operation of electrolyte-gated devices in application-relevant environments.

show abstract

Section: Figuresupporting

confidence: 67%

Section: Figurementioning

confidence: 99%

Section: Figurementioning

confidence: 99%

See 1 more Smart Citation

Energetic Control of Redox‐Active Polymers toward Safe Organic Bioelectronic Materials

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…Improvement of charge carrier mobility and the stability of electroactive compounds is a recent subject of scientific interest, because they are very important properties for the proper function of organic electronic devices . Charge carrier mobility is strongly dependent on the assembly of the conjugated backbone, planarity, density of impurities and structural defects .…”

Section: Introductionmentioning

confidence: 99%

“…[22] Improvement of charge carrier mobility and the stability of electroactive compounds is a recent subject of scientific interest, because they are very important properties for the proper function of organic electronic devices. [23,24] Charge carrier mobility is strongly dependent on the assembly of the conjugated backbone, planarity, density of impurities and structural defects. [25][26][27][28] From a molecular design point of view, attempts to reduce structural and energetic disorder in conjugated polymers have focused on either covalent or noncovalent strategies towards rigidifying the polymer backbone.…”

Section: Introductionmentioning

confidence: 99%

Glycolated Thiophene‐Tetrafluorophenylene Copolymers for Bioelectronic Applications: Synthesis by Direct Heteroarylation Polymerisation

et al. 2019

Self Cite

View full text Add to dashboard Cite

A series of copolymers containing a glycolated 1,4‐dithienyl‐2,3,5,6‐tetrafluorophenylene unit copolymerized with thiophene, bithiophene, thienothiophene and 1,2,4,5‐tetrafluorobenzene comonomer units were designed and synthesised by direct heteroarylation polymerisation. The optical, electrochemical, electrochromic and solid‐state structural properties of the copolymers were investigated. The copolymers exhibit stable redox properties in organic solvents and promising redox properties in thin film configuration with an aqueous electrolyte. Finally, the potential of the copolymers as active materials in organic electrochemical transistors (OECTs) was assessed, and promising performance was shown as an accumulation‐mode OECT material with a peak transconductance of 0.17 mS and a good on/off ratio of 105 for the thiophene copolymer.

show abstract

Materials in Organic Electrochemical Transistors for Bioelectronic Applications: Past, Present, and Future

Moser

Ponder

Wadsworth

et al. 2018

Adv Funct Materials

155

204

View full text Add to dashboard Cite

Organic electrochemical transistors are bioelectronic devices that exploit the coupled nature of ionic and electronic fluxes to achieve superior transducing abilities compared to conventional organic field effect transistors. In particular, the operation of organic electrochemical transistors relies on a channel material capable of conducting both ionic and electronic charge carriers to ensure bulk electrochemical doping. This review explores the various types of organic semiconductors that are employed as channel materials, with a particular focus on the past 5 years, during which the transducing abilities of organic electrochemical transistors have witnessed an almost tenfold increase. Specifically, the structure–property relationships of the various channel materials employed are investigated, highlighting how device performance can be related to functionality at the molecular level. Finally, an outlook on the field is provided, in particular toward the design guidelines of future materials and the challenges ahead in the field.

show abstract

Redox‐Stability of Alkoxy‐BDT Copolymers and their Use for Organic Bioelectronic Devices

Cited by 85 publications

References 34 publications

Energetic Control of Redox‐Active Polymers toward Safe Organic Bioelectronic Materials

Energetic Control of Redox‐Active Polymers toward Safe Organic Bioelectronic Materials

Glycolated Thiophene‐Tetrafluorophenylene Copolymers for Bioelectronic Applications: Synthesis by Direct Heteroarylation Polymerisation

Materials in Organic Electrochemical Transistors for Bioelectronic Applications: Past, Present, and Future

Contact Info

Product

Resources

About