Researchers realize in situ formation of functional materials in living systems

Gold-polymer composites have attracted significant attention in materials science and nanotechnology, particularly for their potential in surface-enhanced Raman scattering. However, challenges such as nanoparticle toxicity, biocompatibility, and cellular uptake still need to be addressed.

Living systems show great potential for functional nanocomposite synthesis, with intracellular in situ methods offering eco-friendly, mild, and spatially controlled advantages over ex vivo approaches. However, it remains a challenge for harnessing cells as natural microreactors to guide the formation of complex nanostructures in vivo.

In a study published in Angewandte Chemie International Edition, Prof. GENG Jin and colleagues from the Shenzhen Institute of Advanced Technology (SIAT) of the Chinese Academy of Sciences realized the in situ synthesis of gold-polymer nanocomposites within living Escherichia coli (E. coli) through a novel strategy based on intracellular polymerization-induced self-assembly (iPISA), which effectively transforms the bacteria into "living nanofactories."

Researchers designed a series of macromolecular chain transfer agents with varying structures and charge properties to initiate self-assembly through reversible addition-fragmentation chain transfer polymerization (RAFT) within living cells. They found that the charge of the resulting polymers significantly influenced their interactions with the cell membrane, as well as the localization of the final products, either inside the cells or on their surfaces.

Moreover, researchers carried out photocatalytic reactions by employing E. coli loaded with gold-polymer nanocomposites. They found that the resulting "hybrid bacteria" could efficiently catalyze aldol condensation under mild conditions, yielding 2-ethylhexenal. In photocatalytic dye degradation experiments using rhodamine B, the system also exhibited excellent catalytic efficiency.

This study demonstrates the potential of living bacteria to construct and deploy functional nanomaterials directly within biological systems, paving the way for innovative applications in green chemistry, catalysis, sensing technologies, and biomanufacturing.