A novel and ultrasensitive fluorescent probe derived from labeled carbon dots for recognitions of copper ions and glyphosate.

Labeling materials with special functional groups are very valuable for the creation of novel probes. Hence, a novel fluorescent probe was constructed by conjugating 4-butyl-3-thiosemicarbazide (BTSC) with carbon dots (CDs). The CDs labeled by BTSC (BTSC-CDs) displayed a strong capability for recognition of Cu and Cu could quench the emission of BTSC-CDs significantly.

Utilizing the interfacial reaction of naphthalenyl thiosemicarbazide-modified carbon dots for the ultrasensitive determination of Fe (III) ions.

Since thiosemicarbazide contains numerous nitrogen and sulfur atoms in its structural formula that enhance its strong coordinating abilities with metal ions, it is always selected as the mother molecule for the design of metal-ion sensors. In this report, a thiosemicarbazide derivative (4-naphthalenyl-3-thiosemicarbazide (NTSC)) was synthesized via a single step process and covalently conjugated onto the surfaces of carbon dots (CDs). The modified CDs demonstrated excellent monodispersity, good photostability, and tunable luminescence properties.