Green-emissive Zn/N co-doped carbon nanodots as a brilliant fluoroprobe for sensitive phosphate detection: logic gate...

The fabrication of Zn and N co-doped carbon nanodots was achieved by a facile and reproducible hydrothermal route utilizing glucosamine hydrochloride (GA) and zinc acetate as precursors. The nanodots offer strong green emission (Gr-CDs), with an λ_ex/λ_em of 360/515 nm. The fluorescence of the Gr-CDs is dropped by phosphate ions (PIs), attributed to the design of a non-luminescent ternary Zn-phosphate-N complex as a result of two arms binding issued from PIs, one associates with the Zn ion of the nanodots shell, and the other binds to the amine moiety of the same nanodots. The obtained results were employed to construct a quenched fluorescence assay for the sensitive detection of PIs, demonstrating a linear relationship between the quenching of luminescence intensity and the PIs concentration in the range 0.6-22 μM. The proposed Gr-CDs nanoprobe was utilized to recognize PIs in environmental water without tedious extraction steps. The nanosensor is also generally applicable and can be suitably extended to detect phosphate-containing compounds for logic gate applications.