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Updated: Jan 22, 2026

Scalable Syntheses of Graphene Oxide and Reduced Graphene Oxide using Cascade Design Oxidation and Highly Basic Reduction Reactions
Published on: July 3, 2025
Exonuclease III-assisted fluorometric aptasensor for the carcinoembryonic antigen using graphene oxide and
Mingjian Chen1, Changbei Ma2, Han Zhao1
1School of Life Sciences, Central South University, Changsha, 410013, China.
Abstract:
A reliable fluorometric assay is described for the determination carcinoembryonic antigen (CEA) using exonuclease III (Exo III) and a 2-aminopurine binding aptamer. In the absence of CEA, dsDNA is degraded by Exo III, and free 2-AP (which has a blue fluorescence with excitation/emission maxima of 310/365 nm) is released. Strong fluorescence is generated after addition of graphene oxide (GO) to the solution. However, the 2-AP modified DNA (T2) cannot be degraded in the presence of CEA by Exo III due to the interaction between CEA and aptamer T1. Hence, only weak fluorescence can be detected after addition of GO. In this system, CEA can be quantified in the 0.05 - 2 ng·mL-1 concentration range with a detection limit of 30 pg·mL-1 (at S/N = 3). The method was successfully applied to analyze serum samples for CEA. Graphical Abstract An exonuclease III-assisted fluorometric aptasensor has been developed for the detection of carcinoembryonic antigen using graphene oxide and 2-aminopurine.
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