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Upconversional Nanoprobes with Highly Efficient Energy Transfer for Ultrasensitive Detection of Alkaline Phosphatase
journal contribution
posted on 2019-10-16, 21:29 authored by Mengping Gao, Ruiying Wu, Qingsong Mei, Cuilan Zhang, Xiao Ling, Shengsong Deng, Hongbo He, Yong ZhangSensitive
detection of alkaline phosphatase (ALP) activity in human
serum is important for diagnosis of various diseases. In this work,
a novel sandwich-structured upconversion nanoparticle, NaYF4:Yb/Er@NaErF4@NaYF4, is fabricated to construct
an upconversional nanoprobe for ultrasensitive detection of phosphate
and ALP activity. The inner shell of NaErF4 bridges the
emitters in the core with the external luminescence quenchers to greatly
improve the energy transfer efficiency. The quencher, herein, is a
coordination complex formed between sulfosalicylic acid and ferric
ions. Owing to the higher affinity for phosphate, ferric ions dissociate
from the complex and potently combine with phosphate ions, thus interrupting
the energy transfer process and recovering the luminescence. This
upconversional nanoprobe shows rapid and sensitive detection of phosphate
with a limit of detection of 2.5 nM. Because ALP catalyzes the hydrolysis
of p-nitrophenyl phosphate to form p-nitrophenol and inorganic phosphate ions, the nanoprobe is further
utilized to achieve sensitive detection of ALP with a limit of detection
of 0.5 μU/mL. This novel strategy offers a new opportunity for
developing sensitive upconversional nanoprobes and many other energy
transfer-based applications.