A novel optical probe based on d‐penicillamine‐functionalized graphene quantum dots: Preparation and application as signal amplification element to minoring of ions in human biofluid

In this study, d ‐penicillamine‐functionalized graphene quantum dots (DPA‐GQD) has been synthesized, which significantly increases the fluorescence intensity of GQD. We used this simple fluorescent probe for metal ions detection in human plasma samples. Designed DPA‐GQD respond to Hg²⁺, Cu²⁺, Au²⁺, Ag⁺, Co²⁺, Zn²⁺, and Pb²⁺ with high sensitivity. The fluorescence intensity of this probe decreased significantly in the presence of metal ions such as, Hg²⁺, Cu²⁺, Au²⁺, Ag⁺, Co²⁺, Zn²⁺, and Pb²⁺. In this work, a promising probe for ions monitoring was introduced. Moreover, DPA‐GQD probe has been tested in plasma samples. The functionalized DPA‐GQDs exhibits great promise as an alternative to previous fluorescent probes for bio‐labeling, sensing, and other biomedical applications in aqueous solution.