Multifunctional AuAgPt Nanoframes for a Stimuli-Responsive Electrochemiluminescence Aptasensor.

Song, Changxiao; Li, Jingxian; Wang, Futing; Peng, Ziyang; Shen, Yan; Huang, Chongyang; Deng, Suping; Yang, Hongfen et al. · ACS Nano · 2025

basic_science · Level V

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Abstract

A multifunctional electrochemiluminescence (ECL) coreaction accelerator, AuAgPt nanoframes (NFs), is described for use in an ECL aptasensor for highly sensitive aflatoxin B1 (AFB1) detection. As a signal quencher, the broad UV-vis absorption spectrum of AuAgPt nanosheets (NSs) overlaps the ECL emission spectrum of g-C<sub>3</sub>N<sub>4</sub>@Au, triggering an ECL resonance energy transfer (ECL-RET). By the adjustment of the dosage of hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>), the AuAgPt NSs are transformed into AuAgPt NFs because H<sub>2</sub>O<sub>2</sub> etches Ag in AuAgPt NSs into Ag<sup>+</sup>, which disrupts the RET process. The as-formed AuAgPt NFs act as a coreaction accelerator to enhance the ECL response of the g-C<sub>3</sub>N<sub>4</sub>@Au/K<sub>2</sub>S<sub>2</sub>O<sub>8</sub> system. Without AFB1, the Ag-dependent DNAzyme is inactive, and a strong ECL signal is observed. After AFB1 is added, the AFB1 aptamer targets AFB1 and the DNAzyme active site is exposed. As-generated Ag<sup>+</sup> further activates DNAzyme to cut the substrate strand (S-DNA), which causes AuAgPt NFs to detach from the electrode surface and the ECL signal to significantly decrease. Under optimal conditions, the proposed ECL aptasensor exhibits high sensitivity with a limit of detection (LOD) of 0.11 fg/mL in the range of 1 fg/mL to 1 μg/mL for AFB1 detection.

Medical subject headings