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Updated: Jan 25, 2026

Phthalic Acid Ester-Binding DNA Aptamer Selection, Characterization, and Application to an Electrochemical Aptasensor
Published on: March 21, 2018
Aptamer based determination of the cancer biomarker HER2 by using phosphate-functionalized MnO2 nanosheets as the
Yuanlin Chai1, Xiaoqing Li1, Minghui Yang2
1College of Chemistry and Chemical Engineering, Hunan Provincial Key Laboratory of Efficient and Clean Utilization of Manganese Resources, Central South University, Changsha, 410083, China.
Abstract:
The authors report a sensitive electrochemical aptamer-based assay for the cancer biomarker human epidermal growth factor receptor-2 (HER2). It is based on the use of MnO2 nanosheets that were functionalized with phosphate and a HER2 binding aptamer and serve as the electrochemical probe. The assay follows a sandwich protocol. A peptide that can specifically recognize HER2 was immobilized on a gold electrode for the capture of HER2. Then, the functionalized MnO2 nanosheets were linked to the electrode via the binding between HER2 and HER2 aptamer on the MnO2 nanosheets. The reaction of phosphate and aptamer on the MnO2 nanosheets with molybdate leads to the formation of redox-active molybdophosphate. This results in dual signal amplification. The generated electrochemical current was measured at 0.22 V (vs. Ag/AgCl). The assay allows HER2 to be determined in the 0.1 to 500 pg·mL-1 concentration range, and the detection limit is as low as 0.05 pg·mL-1. The assay was successfully applied for the detection of HER2 in spiked human serum samples. Graphical abstract Electrochemical detection of breast cancer biomarker human epidermal growth factor receptor-2 (HER2) is reported utilizing phosphate ions and aptamer functionalized MnO2 nanosheet as probe.
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