Ultra-small two dimensional MXene nanosheets for selective and sensitive fluorescence detection of Ag+ and Mn2+ ions

The present work offers a new exploration for the selective sensing of metal ions (Ag+ and Mn2+) via fluorescence quenching of Ti3C2 MXene nanosheets (NSs). Monolayer MXene Ti3C2 NSs exhibited excellent ability to sense Ag+ and Mn2+ ions because of their good hydrophilicity and distinctive surface functionality. The assynthesised Ti3C2 NSs exhibited highest emission fluorescence peak at 461 nm upon the excitation wavelength of 384 nm. The fluorescence emission peak of Ti3C2 NSs was remarkably quenched only upon the addition of Ag+ and Mn2+ ions, exhibiting good linear response between I-o /I and concentration in the range of 0.1-40 mu M and 0.5-60 mu M for Ag+ and Mn2+ ions. The proposed sensor shows lower detection limits of 9.7 and 102 nM for Ag+ and Mn2+ ions with good selectivity. Additionally, the method is effectively applied to detect Ag+ and Mn2+ ions in food and real water samples with excellent recoveries.