Dual electroactive AgM (M=Ru, Pt) NPs for double electroanalysis of HER2 and EpCAM

Parallel multiple detections of tumor markers is of significant for the efficient and accurate early monitoring of related cancers. Electrochemical aptasensors possess excellent selectivity and sensitive quantitative detection while maintaining multiple detection ability. The study of high and different electrochemical beacons is urgent to achieve multiple-level parallel detection. In this work, electroactive AgRu NPs and AgPt NPs were explored to exhibit electrooxidation peaks at 0.8 V and − 0.7 V, respectively. Plasmonic AgRu NPs and AgPt NPs harvested light energy and exhibited amplified electrooxidation activity under local surface plasmon resonance (LSPR) excitation. Plasmon-enhanced electrooxidation principle was proposed for AgM (M=Ru, Pt) NPs owing to the distinct imaginary part of dielectric constants between Ag and platinum group metals (PGM). The strong and non-interference electrooxidation peaks at 0.8 V and − 0.7 V enabled AgRu NPs and AgPt NPs to be different electroactive beacons for the sensitive and reliable quantitative dual detection of human epidermal growth factor receptor-2 (HER2) and epithelial cell adhesion molecule (EpCAM). The LODs were 0.3 pg mL−1 (7.5 amol mL−1) for EpCAM and 0.6 pg mL−1 (3.2 amol mL−1) for HER2. The proposed plasmon-promoted electrooxidation principle provides a novel route for the design of multiple electroactive plasmonic metal-PGM composite electrochemical beacons for simultaneous electroanalysis applications.