A Naphthalimides-Based Probe for Sequential Detection of Cu2+ and PPi and Its Application in Cells Imaging

A novel naphthalimides-based fluorescent probe (NPHD) selectively detected Cu2+ and PPi through "strong yellow-weak green-strong yellow" photonic response in a sequential manner. The formation of NPHD-Cu2+ resulted in obvious fluorescence decreased and wavelength shift from 595 nm to 525 nm by adding Cu2+ to NPHD solution. The mechanism could be attributed to d ->pi* electron transfer (ET) from Cu2+ to NPHD. Furthermore, the NPHD-Cu2+ complex exhibited high selectivity toward PPi through via emission recovery of chemosensor NPHD. The detection limits of NPHD to Cu2+ and NPHD-Cu2+ to PPi were estimated to be 5.72x10(8)M and 2.39x10(8)M. In addition, NPHD could be employed to detect exogenous Cu2+ and PPi in Hep G2 cells.