Ultrasensitive photoelectrochemical immunoassay based on CdS@Cu₂O co-sensitized porous ZnO nanosheets and promoted by multiwalled carbon nanotubes

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• 作者：Hongmei Yang^aAuthor Vitae ; Guoqiang Sun^aAuthor Vitae ; Lina Zhang^bAuthor Vitae ; Yan Zhang^aAuthor Vitae ; Xianrang Song^cAuthor Vitae ; Jinghua Yu^a ; ^{ujn.yujh@gmail.com" class="auth_mail" title="E-mail the corresponding author}Author Vitae ; Shenguang Ge^a ; ^bAuthor Vitae
• 关键词：Photoelectrochemical ; CdS@Cu2O ; Porous ZnO nanosheets ; Co-sensitized ; Carcinoembryonic antigen
• 刊名：Sensors & Actuators: B. Chemical
• 出版年：2016
• 出版时间：29 October 2016
• 年：2016
• 卷：234
• 期：Complete
• 页码：658-666
• 全文大小：2444 K

文摘

An ultrasensitive photoelectrochemical (PEC) immunosensor for the detection of carcinoembryonic antigen (CEA) was constructed using CdS@Cu₂O co-sensitized porous ZnO nanosheets as photoactive materials and multiwalled carbon nanotubes (MWCNTs) as electrons sink. Porous ZnO was assembled on the MWCNTs modified indium tin oxides electrode to immobilize capture antibodies. With a sandwich immunoassay format, CEA and signal antibodies labeled CdS@Cu₂O were introduced in sequence via specific immunoreaction, and the ultrahigh sensitivity of this immunoassay results from the following three aspects. First, the co-sensitization of Cu₂O and CdS extends the absorption range of ZnO from ultraviolet region to visible light region, which can adequately utilize the light energy. Second, the effective matching of energy levels between the ZnO, CdS and Cu₂O accelerates the separation and transfer of photogenerated electron-hole pairs and improves the PEC performance, significantly. Finally, the introduced MWCNTs evidently expedite the interfacial electron transfer from ZnO to electrode, further resulting in noticeably increased photocurrent. On the basis of multiple signal amplification strategy, a largely increased linear detection range from 1.0 pg mL⁻¹ to 80 ng mL⁻¹ with a low detection limit (0.4 pg mL⁻¹) are obtained. Meanwhile, the prepared materials with attractive properties provide a promising platform for PEC detection.