Bovine serum albumin functionalized blue emitting Ti3C2 MXene quantum dots as a sensitive fluorescence probe for Fe3+ ion detection and its toxicity analysis

In the present work, an improved class of protein functionalized fluorescent 2D Ti₃C₂ MXene quantum dots (MXene QDs) was prepared using a hydrothermal method. Exfoliated 2D Ti₃C₂ 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 Fe³⁺ 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 Fe³⁺ 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 Fe³⁺ 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.