A three-dimensional CoNi-MOF nanosheet array-based immunosensor for sensitive monitoring of human chorionic gonadotropin with core–shell ZnNi-MOF@Nile Blue nanotags. Issue 24 (21st October 2020)

• Record Type: Journal Article
• Authors: Lu, Wenbo; Chen, Zi-Ang; Wei, Ming; Cao, Xiaowei; Sun, Xuping
• Is Part Of: Analyst. Volume 145:Issue 24(2020)
• Page Start: 8097
• Page End: 8103
• Publication Date: 2020-10-21
• Subjects: Chemistry, Analytic -- Periodicals; 543
• DOI: 10.1039/d0an01648a
• Languages: English
• ISSNs: 0003-2654

Abstract

Abstract : A sandwich-type electrochemical immunosensor for HCG detection based on a CoNi-MOF nanosheet-array and Nile Blue@ZnNi-MOF spheres is successfully exploited. Abstract : A CoNi-based metal–organic framework (CoNi-MOF) nanosheet array is synthesized by the treatment of a CoNi layered double hydroxide nanosheet array on Ni foam with 3, 5-diaminobenzoic acid. The CoNi-MOF nanosheet array with amino and carboxyl groups can be used to capture the human chorionic gonadotropin (HCG) primary antibody (HCG Ab1). Nile Blue decorated ZnNi-MOF (NB@ZnNi-MOF) spheres immobilized with HCG secondary antibodies (HCG Ab2) are used for signal amplification. When HCG exists in an analytical sample, a sandwich structure is formed and an electrochemical signal is produced. The analytical signal generated during the detection is caused by the conversion of Co(ii ) and Co(iii ) in the CoNi-MOF nanosheet array. The Nile Blue of the NB@ZnNi-MOF sphere, as a kind of redox-active species, is responsible for the electrochemical signal amplification in the immunosensor. On the basis of the above advantages, the HCG immunosensor exhibits a lower limit of detection (1.85 × 10 −3 mIU mL −1 ) and a wide linear range from 0.005 mIU mL −1 to 250 mIU mL −1 . Additionally, this immunosensor is used to quantitatively detect HCG in human blood serum and shows good correlations with the standard enzyme-linked immunosorbent assay (ELISA), providing a high value on clinical diagnosis.