# Counteranion Effects on the Incorporation of Photosystem I with Poly(3,4-ethylenedioxythiophene) (PEDOT)

## TL;DR

This study explores how different counteranions affect the performance of a conductive polymer when combined with a photosystem for energy applications.

## Contribution

The paper provides the first detailed study on counteranion effects in PEDOT films interfaced with Photosystem I.

## Key findings

- PEDOT films with bromide anions produced the highest photocurrent output.
- The porous leaf-like structure of the polymer matrix influenced photoactivity.
- Counteranion choice significantly impacts film morphology and electrical properties.

## Abstract

Conductive polymers provide an effective interface for
proteins,
particularly in photovoltaic applications. The synthetic toolbox affords
a variety of options in which to fine-tune protein–polymer
properties toward better engineered materials. While prior work has
shown compatibility between Poly(3,4-ethylenedioxythiophene) (PEDOT)
and Photosystem I, a detailed study of counteranion effects with interfacing
Photosystem I has yet to be performed. This study, which fills a significant
gap in the field, involves the synthesis of PEDOT films with a variety
of different potassium-based salts. Morphology, capacitance, and impedances
all varied across the films when deposited in the presence of the
different anions. These properties were evaluated independently before
interfacing PSI. After incorporating PSI within these films through
entrapment and deposition approaches, the counteranion dependent properties
were explored further through the photoactivity of these composite
films. Results showed that films produced with the bromide anion provided
the highest photocurrent output due to the porous leaf-like structure
of the conducting polymer matrix.