Smart probe for simultaneous detection of copper ion, pyrophosphate, and alkaline phosphatase in vitro and in clinical samples

Wilson's disease (WD), which might lead to acute liver failure, is an inherited disorder characterized by accumulation of copper (Cu2+) in the brain, the liver, and other vital organs. In the clinic, decreased serum alkaline phosphatase (ALP) concentration is used for WD diagnosis. But to the best of our knowledge, using a fluorescent probe to simultaneously detect multiple factors in WD (e.g., Cu2+, pyrophosphate (PPi), and ALP) has not been reported. Herein, we rationally designed a fluorescent switch (E)-8-((4-methylbenzylidene)amino)napthalen-1-amine (L) and successfully applied it for sequential and selective detections of Cu2+, PPi, and ALP in vitro, in living cells and synovial fluid samples with "Off," "On," and "Off" fluorescence signals, respectively. Considering the obvious correlations among Cu2+, PPi, and ALP in WD, we envision that our fluorescent probe L could be applied to in vitro diagnosing WD in the near future.