Enhancing carbon capture efficiency with a large-sized bionic jellyfish-carbonic anhydrase complex

Abstract

Enzymatic CO₂ capture technology is a promising approach for carbon neutralization that resembles photosynthesis and shows great potential. Enzyme immobilization can enhance the stability of enzyme structure and reduce the cost of enzymatic carbon capture. However, severe solid (immobilized enzyme)–gas (CO₂) mass transfer barriers lead to low catalytic efficiency. Studies have been able to reduce the size of substrates to improve mass transfer efficiency, but the associated processes resulted in a tradeoff between “easy mass transfer” and “difficult recycling” for small sizes. In this study, a bionic jellyfish-carbonic anhydrase (Bj-CA) complex was developed based on the predation mechanism of jellyfish, with superior mass transfer and ease of recovery. A lightweight, transparent, and large low-density polyethylene (LDPE) film served as the jellyfish “umbrella,” while the ultra-soft poly(glycidyl methacrylate)/poly(lysine) molecular chain functioned as the “tentacle.” The robust Bj-CA complex was prepared by mosaicking “stinging cells” carbonic anhydrase (CA) on jellyfish tentacles. By optimizing the length and density of the tentacles, maximum flexibility was achieved, enabling CA to undergo extensive flexible displacement along the tentacles and minimizing the mass transfer barriers in large systems. The results indicated that the as-prepared Bj-CA achieved 83% of the CO₂ capture efficiency of the free enzyme. Notably, the complex can be easily recycled through “extraction” and retain 60% of its enzymatic activity after 15 cycles, which is extremely challenging for small-sized substrates. This study contributes to the large-scale development of robust enzymatic carbon capture integrated devices.