▎ 摘　　要

The analysis of circulating tumor DNA (ctDNA) turns out to be increasingly significant considering its potential value in the clinical diagnosis of cancer. Herein, a ctDNA electrochemical biosensor was developed with a low detection limit and high selectivity by using three-dimensional graphene-like homogeneous carbon architecture (3D-GHC600) loaded with gold-platinum (AuPt). The 3D-GHC600 was derived from the annealing process of copper-based metal-organic framework (denoted as Cu-BTC) at the optimal temperature (600 ?), which includes the merits of large area, rich mesopores, homogeneous size and morphology, and 3D structure. AuPt was formed on the 3D-GHC(600) surface via an in-situ reduction reaction. Characterizations demonstrated that the resultant composite catalyst (AuPt/3DGHC600) was prepared successfully and exhibited remarkable electrochemical properties. Further, the catalyst was used as a label of signal probes (SPs) to form SPs-label. The hybridization reactions were completed by layer-by-layer recognition of capture probes (CPs), target DNA (tDNA), and SPs-label on the electrode, thus forming a sandwich-like structure. The current signals of the SPs-label toward the electrocatalytic reduction of H2O2 were recorded in all tests for tDNA analysis. Accordingly, this recommended biosensor of tDNA showed good performance including a wide linear range of 10(-8) M 10(-17) M with a detection limit of 2.25 x 10-18 M (S/N = 3), excellent selectivity for the recognition of different interferences, satisfying reproducibility, good stability, and outstanding recovery. These results demonstrated the promising application of the biosensor in the detection of ctDNA. (C)& nbsp;2022 Elsevier Ltd. All rights reserved.