As significant biocatalysts, natural enzymes have exhibited a vast range of applications in biocatalytic reactions. However, the “always-on” natural enzyme activity is not beneficial for the regulation of catalytic processes, which limits their bio-applications. Recently, it has been extensively reported that various organic artificial enzymes exhibit prominent absorption and controlled activity under illumination, which not only creates a series of light-responsive catalytic platforms but also plays a key role in biosensing and biomedical research. To provide novel ideas for the design of artificial enzymes, we conduct this review to highlight the recent progress of light-responsive organic artificial enzymes (LOA-Enz). The specific photoresponse mechanism and various bio-applications of LOA-Enz are also presented in detail. Furthermore, the remaining challenges and future perspectives in this field are discussed.

A highly active and stable oxygen evolution reaction (OER) electrocatalyst is critical for hydrogen production from water splitting. Herein, three-dimensional Ni₃S₂@graphene@Co₉₂S₈ (Ni₃S₂@G@Co₉S₈), a sandwich-structured OER electrocatalyst, was grown in situ on nickel foam; it afforded an enhanced catalytic performance when highly conductive graphene is introduced as an intermediary for enhancing the electron transfer rate and stability. Serving as a free-standing electrocatalytic electrode, Ni₃S₂@G@Co₉S₈ presents excellent electrocatalytic activities for OER: A low onset overpotential (2 mA·cm^-2 at 174 mV), large anode current density (10 mA·cm^-2 at an overpotential of 210 mV), low Tafel slope (66 mV·dec^-1), and predominant durability of over 96 h (releasing a current density of ~14 mA·cm^-2 with a low and constant overpotential of 215 mV) in a 1 M KOH solution. This work provides a promising, cost-efficient electrocatalyst and sheds new light on improving the electrochemical performance of composites through enhancing the electron transfer rate and stability by introducing graphene as an intermediary.