Functionalization Strategies of PEDOT and PEDOT:PSS Films for Organic Bioelectronics Applications

Abstract

Organic bioelectronics involves the connection of organic semiconductors with living organisms, organs, tissues, cells, membranes, proteins, and even small molecules. In recent years, this field has received great interest due to the development of all kinds of devices architectures, enabling the detection of several relevant biomarkers, the stimulation and sensing of cells and tissues, and the recording of electrophysiological signals, among others. In this review, we discuss recent functionalization approaches for PEDOT and PEDOT:PSS films with the aim of integrating biomolecules for the fabrication of bioelectronics platforms. As the choice of the strategy is determined by the conducting polymer synthesis method, initially PEDOT and PEDOT:PSS films preparation methods are presented. Later, a wide variety of PEDOT functionalization approaches are discussed, together with bioconjugation techniques to develop efficient organic-biological interfaces. Finally, and by making use of these approaches, the fabrication of different platforms towards organic bioelectronics devices is reviewed.

Poly(3,4‐ethylenedioxythiophene):Poly(styrene sulfonate) in antibacterial, tissue engineering and biosensors applications: Progress, challenges and perspectives

“…To adjust the desirable properties, special attention is still required for altering the structure of PEDOT:PSS materials by different functionalization or substitution techniques. Also, selection and distribution of numerous additives are very important for altering the structural properties of PEDOT:PSS 145 . In the future, it is important to develop high performance and cost effective techniques and processes for commercialization.…”

PEDOT-NHS as a Versatile Conjugated Polyelectrolyte for Bioelectronics

“…Of the reported EDOT derivatives for biofunctionalization, 20,36 surface deposition via electropolymerization remains the polymerization method of choice, [37][38][39][40] precluding water-processible materials and solution processing of biomaterials. Recently direct (hetero)arylation polymerization (DHAP) has been utilized as a tool to develop anionic, water processible copolymers with opto(electronic) properties analogous to those synthesized through chemical oxidative polymerization.…”

“…PEDOT-S and PEDOT:PSS have been incorporated into biomaterials for various bioelectronic applications, 15,22,43,45 however their lack of chemical handles for functionalization has required the use of rudimentary blending and soaking procedures. 36,46 The physical entrapment of conductive polymers within a biomaterial, rather than chemical binding, allows for potential loss of the polymer over time and therefore decreased bioelectronic performance or increased toxicity to the cellular environment. Relatively low loadings of EDOT-NHS structural units were targeted within the PEDOT-NHS copolymers (10% and 50%) to support biofunctionalization via amidation of the activated NHS-ester, while minimizing the loss of alkyl sulfonate groups required to selfdope the polymer.…”

Advanced Functional Membranes for Sensor Technologies

“…Furthermore, these membranes must be non-toxic and biocompatible to minimize the risk of epithelialization or allergic reactions. In this context, the use of enzymes [54][55][56][57], hydrogels [6,41,[58][59][60], and conductive polymers such as polyaniline (PANI) [61][62][63][64], polypyrrole (PPy) [65][66][67], polythiophene (PT) [68][69][70], or polyethylene dioxide thiophene (PEDOT) [43,[71][72][73][74] has been reported for the development of bioelectrodes due to their biocompatibility, conductivity, and the presence of tunable functionalities. However, its application in the development of biosensors is limited by different reasons and challenges to overcome, such as its relative fragility; its decrease in properties against variations in the pH of the medium, possible degradation in toxic or reactive compounds; and in some cases the use of synthesis processes and complex manufacturing procedures that are difficult to implement outside the laboratory scale [70][71][72][73][74][75][76].…”