Soluble non-toxic carbon nano-rods for the selective sensing of iron(iii) and chromium(vi)

Herein, we report a simpler functionalization of the CNR by the amine (2,2′-(ethylenedioxy)-bis(ethylamine)) (H ₂NCH ₂CH ₂OCH ₂CH ₂OCH ₂CH ₂NH ₂ (EDA)) molecules as a surface passivating agent to achieve soluble functionalized carbon nano-rods (f-CNR). The surface-functionalized fluorescent f-CNR exhibited the quantum yield value of ∼16% and were used as a fluorescent probe for the selective detection of the Cr(vi) and Fe(iii) ions in a homogeneous aqueous phase based on fluorescence quenching. In particular, the limits of the detection for both metal ions were obtained to be ∼43 nM for Fe(iii) and ∼11 nM for Cr(vi), which were quite significant in aqueous media. Moreover, the f-CNR showed non-toxicity and was biocompatible with Escherichia coli (E. coli) (ATCC 25922) cells when tested up to 9 mg mL ^-1.