Inspired by the complexity and versatility of nature’s catalysts: enzymes, artificial biocatalysts have been of large interest for their applicability to non-natural syntheses. However, the limitations of these systems, such as substrate specificity, selectivity, and solubility, call for novel approaches. In this poster, we report the progress on developing single-chain polymer nanoparticles (SCNPs) as a modular, recyclable, and efficient class of catalysts for light-mediated [2+2] and [4+2] cycloadditions.