Fabrication of water-soluble blue emitting molybdenum nanoclusters for sensitive detection of cancer drug methotrexate

Abstract

• 6-aza 2-thiothymine was as a ligand for fabrication of fluorescent Mo NCs. • ATT-Mo NCs showed a strong emission peak at 448 nm when excited at 370 nm. • ATT-Mo NCs acted as a sensor for sensing of methotrexate. • ATT-Mo NCs-based fluorescence method exhibited impressive detection limit of 1.28 nM. • Methotrexate was quantified in its pharmaceutical compositions. Fluorescent metal nanoclusters have been widely applied for sensing of biologically active species, drugs and biomolecules. Herein, fabrication of molybdenum nanoclusters is performed via ligand mediated synthesis where 6-aza-2-thiothymine (ATT) is used as a capping agent. The as-synthesized ATT-Mo NCs have shown high ability to recognize cancer drug methotrexate. The as-prepared ATT-Mo NCs exhibited a quantum yield of 14.34%, and good stability, showing λ Em/Ex = 448/370 nm. Significantly, the fluorescence intensity of ATT-Mo NCs was effectively quenched with addition of MTX drug, showing a linear response toward MTX in the range of 62 nM – 10 μM, with a detection limit of 1.28 nM. Moreover, the as-synthesized ATT-Mo NCs have proven to be an inexpensive analytical method for the selective assay of methotrexate in real biological samples (urine). This method also shows practical applicability for the detection of methotrexate in its pharmaceutical compositions.