Solution‐Deposited and Patternable Conductive Polymer Thin‐Film Electrodes for Microbial Bioelectronics

Abstract

Microbial bioelectronic devices integrate naturally occurring or synthetically engineered electroactive microbes with microelectronics. These devices have a broad range of potential applications, but engineering the biotic–abiotic interface for biocompatibility, adhesion, electron transfer, and maximum surface area remains a challenge. Prior approaches to interface modification lack simple processability, the ability to pattern the materials, and/or a significant enhancement in currents. Here, a novel conductive polymer coating that significantly enhances current densities relative to unmodified electrodes in microbial bioelectronics is reported. The coating is based on a blend of poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS) crosslinked with poly(2‐hydroxyethylacrylate) (PHEA) along with a thin polydopamine (PDA) layer for adhesion to an underlying indium tin oxide (ITO) electrode. When used as an interface layer with the current‐producing bacterium Shewanella oneidensis MR‐1, this material produces a 178‐fold increase in the current density compared to unmodified electrodes, a current gain that is higher than previously reported thin‐film 2D coatings and 3D conductive polymer coatings. The chemistry, morphology, and electronic properties of the coatings are characterized and the implementation of these coated electrodes for use in microbial fuel cells, multiplexed bioelectronic devices, and organic electrochemical transistor based microbial sensors are demonstrated. It is envisioned that this simple coating will advance the development of microbial bioelectronic devices.

Light-Induced Patterning of Electroactive Bacterial Biofilms

“…60−64 Additionally, a recent study developed a novel conductive polymer coating that enabled the selective deposition of Shewanella cells only on a desired region of an electrode surface. 65 Compared with these previous works, our strategy does not require electrode pretreatment for electroactive biofilm patterning and can generate robust biofilms with defined dimensions. As demonstrated in this work, this technique can enable tunable biofilm conduction and electrochemical activity by controlling the amount and location of electroactive cells on unmodified transparent working electrodes.…”

“…Prior efforts to direct electroactive biofilm formation on surfaces have focused solely on engineering cell–electrode attachment, rather than patterning, through synthetic biology and materials engineering strategies. These works were based on either (I) enhancing biofilm formation by expressing adhesive appendages on cell surfaces , and increasing c -di-GMP levels , or (II) placing complementary chemical or DNA-based structures on substrates and cell surfaces to bond cells to electrodes. − Additionally, a recent study developed a novel conductive polymer coating that enabled the selective deposition of Shewanella cells only on a desired region of an electrode surface . Compared with these previous works, our strategy does not require electrode pretreatment for electroactive biofilm patterning and can generate robust biofilms with defined dimensions.…”

Engineered Living Materials For Sustainability

“…These materials exhibit tunable conductivity and excellent biocompatibility and have been widely used in organic electronics. Tseng et al proposed constructing compatible interfaces between electrodes and microorganisms using PEDOT:PSS . The S.…”

Enhanced transmembrane electron transfer in Shewanella oneidensis MR-1 using gold nanoparticles for high-performance microbial fuel cells

“…17 In recent years, substantial efforts have been centered on improving the DET efficiency through modifying electrodes with various functional nanomaterials, 18,19 including carbonaceous material, [20][21][22] metals, 23 metal oxides 24 and conducting polymers. 25 Highly conductive nanomaterials can act as electron transport channels for bacteria and thus signicantly improve the EET efficiency. 26 Moreover, the additional active sites introduced by them can improve interfacial electron transfer between bacteria and the electrode, leading to efficient biocatalysis and electrocatalysis.…”