Scientists at the Institute of Nano Science and Technology (INST), Mohali, have discovered that a naturally occurring bacterial protein can act as a light-responsive semiconductor, a breakthrough that could shape the future of eco-friendly and biocompatible electronics.
The team found that a self-assembling bacterial shell protein, previously known for forming stable two-dimensional structures, exhibits semiconducting and photoactive properties without any synthetic additives, metals, or external power sources. This discovery offers a sustainable alternative to conventional semiconductor materials like silicon, which are rigid, energy-intensive to produce, and contribute significantly to electronic waste.
Led by Dr. Sharmistha Sinha, with researchers Silky Bedi and S. M. Rose, the team explored whether the protein’s naturally ordered, electron-rich structure could conduct electricity when exposed to light. Experiments showed that thin films of the protein absorb ultraviolet light and generate an electrical current on their own. This effect is driven by tyrosine, a naturally occurring amino acid in the protein, which releases electrons when illuminated. The resulting movement of electrons and protons across the organized protein surface functions similarly to a miniature solar cell.
Advanced microscopy and electrical testing confirmed that the semiconducting behaviour relies on the protein’s precise self-assembled structure and the orientation of its tyrosine residues. Comparative studies with disordered proteins containing tyrosine showed that this response is unique to the naturally organized protein sheets.
Published inChemical Scienceby the Royal Society of Chemistry, the findings open new avenues in bio-inspired electronics. The protein’s flexibility, non-toxicity, and biocompatibility make it suitable for wearable health monitors, UV-sensing skin patches, implantable medical devices, and biodegradable environmental sensors that safely decompose after use.
Researchers suggest that this discovery highlights the potential of leveraging natural molecular architectures to design next-generation electronic materials. Protein-based semiconductors could enable low-energy, genetically tunable, and environmentally responsible technologies for sensors, detectors, and medical devices, combining innovation with sustainability.
