A "weak acid and weak base" type fluorescent probe for sensing pH: mechanism and application in living cells.

ABSTRACT: A simple pH fluorescent probe, N-(6-morpholino-1, 3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl) isonicotinamide (NDI), based on naphthalimide as the fluorophore and isonicotinic acid hydrazide as the reaction site was synthesized and characterized. It is useful for monitoring acidic and alkaline pH. The results of pH titration indicated that NDI exhibits obvious emission enhancement with a pK _a of 4.50 and linear response to small pH fluctuations within the acidic range of 3.00-6.50. Interestingly, NDI also displayed strong pH-dependent characteristics with pK _a 9.34 and linearly responded to an alkaline range of 8.30-10.50. The sensing response mechanism was confirmed by ¹H NMR and ESI-MS spectroscopy. The mechanism of

SUBMITTER: Jiao C 

PROVIDER: S-EPMC9066030 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature