Bovine serum albumin functionalized blue emitting Ti 3 C 2 MXene quantum dots as a sensitive fluorescence probe for Fe 3+ ion detection and its toxicity analysis.

In the present work, an improved class of protein functionalized fluorescent 2D Ti ₃ C ₂ MXene quantum dots (MXene QDs) was prepared using a hydrothermal method. Exfoliated 2D Ti ₃ C ₂ sheets were used as the starting precursor and transport protein bovine serum albumin (BSA) was used to functionalize the MXene QDs. BSA-functionalized MXene QDs exhibited excellent photophysical property and stability at various physiological parameters. High-resolution transmission electron microscopy analysis showed that the BSA@MXene QDs were quasispherical in shape with a size of ~2 nm. The fluorescence intensity of BSA@MXene QDs was selectively quenched in the presence of Fe ³⁺ ions. The mechanism of fluorescence quenching was further substantiated using time-resolved fluorescence and Stern-Volmer analysis. The sensing assay showed a linear response within the concentration range 0-150 μM of Fe ³⁺ ions with excellent limit of detection. BSA@MXene QDs probe showed good selectivity toward ferric ions even in the presence of other potential interferences. The practical applicability of BSA@MXene QDs was further tested in real samples for Fe ³⁺ ion quantification and the sensor had good recovery rates. The cytotoxicity studies of the BSA@MXene QDs toward the human glioblastoma cells revealed that BSA@MXene QDs are biocompatible at lower doses and showed significant cytotoxicity at higher dosages.
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