Silk Fibroin-Templated Copper Nanoclusters: Responsive Fluorescent Probes Exhibiting 2,4-Dichlorophenoxyacetic Acid-Enhanced Emission and p-Nitrophenol-Induced Quenching.

ABSTRACT: In this work, highly water-soluble silk fibroin (SF) is first prepared by recrystallizing degummed silkworm cocoon fibers in concentrated CaCl₂ solution (replacing the conventional Ajisawa's reagent), and then used as both stabilizing and reducing agents to synthesize copper nanoclusters (Cu@SF NCs) at pH = 11. Due to the existence of unreacted Cu²⁺ ions, the resulting SF-templated Cu NCs form slight aggregates, yielding a purple-colored solution with blue fluorescence. Interestingly, upon adding the pesticide 2,4-dichlorophenoxyacetic acid (2,4-D), the Cu NCs aggregates disassemble and the fluorescence is significantly enhanced, creating a "fluorescence-on" sensor for 2,4-D with a detection limit of 0.65 μM. In contrast, the pollutant p-nitrophenol (p-NP) quenches th

SUBMITTER: Qin N 

PROVIDER: S-EPMC12899482 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature