Study on the interaction between CdTe quantum dots and folic acid by two-photon excited fluorescence spectroscopic techniques

Water-soluble CdTe QDs modified by thioglycolic acid were synthesized with a facile one-pot method. Two-photon excited fluorescence spectroscopic technique was used to study the interaction between TGA-capped CdTe quantum dots and folic acid. Experiments results showed that the two-photon fluorescence of TGA-capped CdTe QDs in PBS buffer solution was quenched in the presence of folic acid. A good linear relationship was observed between the two-photon fluorescence intensity of TGA-capped CdTe QDs and the concentration of folic acid. The two-photon excited fluorescence quenching mechanism was also presented.

► Two-photon excited fluorescence has minimum autofluorescence interference.
► The technique has wider linear range of detecting FA.
► The technique has better precision.
► Application of two-photon excited fluorescence broadens.