Production of carbon dots by pulsed laser ablation: Precursors and photo‐oxidase properties

Abstract Light is indispensable in many biomedical reactions, but there are few nanomaterials capable of light‐activated enzyme‐like activities. In this work, carbon dots (C‐dots) were prepared through one‐step pulsed laser ablation (PLA) treatment of polymers in aqueous solution. The choice of water‐soluble polymers as starting materials could extend the types of carbon sources for PLA reactions. The obtained C‐dots aqueous solution with blue fluorescence could be used directly without any centrifugation and purification. The light‐induced oxidase‐like activity of C‐dots was exploited in sensing Cu 2+ ions for the first time. The sensing mechanism was speculated that the decrease in reactive oxygen species (ROS) through the photo‐induced electron transfer (PET) process between C‐dots and Cu 2+ , thereby inhibiting their photo‐oxidase activity. This work provides a new colorimetric method to detect Cu 2+ without using the well‐known fluorescence of C‐dots.