Ratiometric Electrochemiluminescent Immunoassay for Tumor Marker Regulated by Mesocrystals and Biomimetic Catalyst

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• 作者：Qingrong Zhang^a ; Hong Dai^a ; ^{dhong@fjnu.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Ting Wang^b ; Yilin Li^a ; Shupei Zhang^a ; Guifang Xu^a ; Sihong Chen^a ; Yanyu Lin^a
• 关键词：Ratiometric ; ECL biosensor ; Octahedral anatase mesocrystals ; Dual-signal amplification ; Competitive immunoreaction
• 刊名：Electrochimica Acta
• 出版年：2016
• 出版时间：1 April 2016
• 年：2016
• 卷：196
• 期：Complete
• 页码：565-571
• 全文大小：1976 K

文摘

In this work, a ratiometric electrochemiluminescent immunosensor on octahedral anatase mesocrystals (OAM) support for the ultrasensitive determination of alpha-fetal protein (AFP) by exploiting chitosan functionalized silver iodide (CS-AgI) as biomimetic catalyst was developed. The proposed system was achieved by choosing luminol and potassium persulfate (K₂S₂O₈) as promising ECL emitter units, due to the potential-resolved property and maximum emission wavelength-resolved property of them. And OAM with high porosity, oriented subunit alignment and large surface area was adopted to adsorb luminol to form solid state ECL and as affinity support to immobilize abounding antibodies of AFP (Ab) firstly. Furthermore, CS-AgI was found to possess biomimetic catalyst activity, which could catalyze the decomposition of hydrogen peroxide that as the common coreactant both of luminol and K₂S₂O₈ and thus the dual ECL responses was amplified. When the biosensor incubated in the mixture solution of CS-AgI labeled AFP (CS-AgI@AFP) and the target AFP, owing to the competitive recognition of the CS-AgI@AFP and the target AFP with Ab, the amount of the CS-AgI@AFP captured by the immobilized Ab reduced with the increasing concentration of AFP, accordingly, the dual ECL responses decreased. Upon the basis of the ratio of ECL intensities at two excitation potentials, this proposed ratiometric ECL strategy achieved ultrasensitive determination for the alpha-fetal protein via competitive immunoreaction with a wide linear detection range of 1 fg/ml to 20 ng/ml and a detection limit was 1 fg/ml.