[Published]: Electrochemically Driven Optical Dynamics of Reflectin Protein Films

[Octobot]

Neuronally triggered phosphorylation drives the dynamic condensation of reflectin proteins, enabling squid to fine tune the colors reflected from specialized skin cells (iridocytes) for camouflage and communication. Reflectin, the primary component of iridocyte lamellae, forms alternating layers of protein and low refractive index extracellular space within membrane-encapsulated structures, acting as a biologically tunable distributed Bragg reflector. In vivo, reflectin condensation induces...

Adv Mater. 2025 Feb 17:e2411005. doi: 10.1002/adma.202411005. Online ahead of print.

ABSTRACT

Neuronally triggered phosphorylation drives the dynamic condensation of reflectin proteins, enabling squid to fine tune the colors reflected from specialized skin cells (iridocytes) for camouflage and communication. Reflectin, the primary component of iridocyte lamellae, forms alternating layers of protein and low refractive index extracellular space within membrane-encapsulated structures, acting as a biologically tunable distributed Bragg reflector. In vivo, reflectin condensation induces osmotic dehydration of these lamellae, reducing their thickness and shifting the wavelength of reflected light. Inspired by this natural mechanism, we demonstrate that electrochemical reduction of imidazolium moieties within the protein provides a reversible and tunable method to control the water volume fraction in reflectin thin films, allowing precise, dynamic modulation of the film's refractive index and thickness - mimicking the squid's dynamic color adaptation. To unravel the underlying mechanisms, we developed electrochemical correlative ellipsometry and surface plasmon resonance spectroscopy, enabling real-time analysis of optical property changes of reflectin films. This electrochemically driven approach offers unprecedented control over reflectin condensation dynamics. Our findings not only deepen the understanding of biophysical processes governing cephalopod coloration but also pave the way for bio-inspired materials and devices that seamlessly integrate biological principles with synthetic systems to bridge the biotic-abiotic gap.

PMID:39961049 | DOI:10.1002/adma.202411005

Yin-Chen Lin, Changxuan Yang, Seren Tochikura, Joshua R Uzarski, Daniel E Morse, Lior Sepunaru, Michael J Gordon

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[tonmo]

I asked TONMO's Xpertloop to summarize the significance of this research:

Scientists have demonstrated that reflectin proteins, which enable cephalopod camouflage, can be electrically controlled in thin films, paving the way for bio-inspired materials that dynamically manipulate light.

In cephalopods, these proteins rearrange in response to signals from their nervous system, affecting the way their skin interacts with light. By mimicking this response in a lab setting, scientists are getting closer to replicating cephalopod camouflage in applications like adaptive clothing, dynamic displays, and even biomedical technology.