Calum T. J. Ferguson

The design and development of artificial metal‐free photoenzymes aims to combine the selectivity of enzymatic reactions with the benefits of modern synthetic photocatalysts. Removing the need for rare earth metals and allowing for milder reaction conditions, leading to a more sustainable catalytic system. Here, we present the design of a novel artificial photoenzyme by integrating an organophotocatalytic moiety based on a donor‐acceptor design into a steroid carrier protein (SCP‐2L). SCP‐2L possesses a hydrophobic tunnel facilitating substrate binding in aqueous media. The photocatalyst was site‐selectively bound to three SCP‐2L variants, possessing a non‐native cysteine residue strategically placed around the hydrophobic tunnel of the protein. The three modified photoenzymes were shown to be selective for the oxidation of organic sulfides giving up to 192 turnovers.

The emergence of heterogeneous photocatalysis has facilitated redox reactions with high efficiency, without compromising the recyclability of the photocatalyst. Recently, stimuli‐responsive heterogeneous photocatalytic materials have emerged as a powerful synthetic tool, with simple and rapid recovery, as well as an enhanced dynamic control over reactions. Stimuli‐responsive polymers are often inexpensive and easy to produce. They can be switched from an active “on” state to an inert “off” state in response to external stimuli, allowing the production of photocatalyst with adaptability, recyclability, and orthogonal control on different chemical reactions. Despite this versatility, the application of artificial smart material in the field of heterogeneous photocatalysis has not yet been maximized. In this Minireview, we will examine the recent developments of this emerging class of stimuli‐responsive heterogeneous photocatalytic systems. We will discuss the synthesis route of appending photoactive components into different triggerable systems and, in particular, the controlled activation and recovery of the materials.