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

Sonia Kiran,Renuka Khatik,Romana Schirhagl

doi:10.1007/s00216-019-02027-2

Abstract

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.

Highlights

Copper is present as trace element in the human body
After confirming the fluorescence property of L, we tested its capability for Cu2+ detection
The FI at 415 nm and Cu2+ concentration showed a linear relation (Y = 3095.32 − 74.35*X, R2 = 0.98) over the range of 0–40 μM and the limit of detection (LOD) of Cu2+ was measured to be 2.60 μM according to the 3σ method (Fig. 1b), which is comparable with those of recently reported fluorescence probes for Cu2+

Summary

Introduction

Copper is present as trace element in the human body. It is crucial for various physiological activities like functioning of proteins, expressing genes [1], and operating of the human nerve system [2]. Nucleic acid sensors [9] and new “Off” (or “On”) fluorescent probes [10,11,12,13,14] have been introduced for the detection of Cu2+ with excellent sensitivity and good accuracy. Often they require harsh reaction conditions, tedious sample preparation procedures, and chemical and physical interference with coexisting metal ion or inadequate biocompatibility [15]

Methods

Results

Conclusion