Persistent luminescence materials (PLMs) have been capturing more and more attention in biosensing, which is ascribed to the autoluminescence-free background, no requirement of illumination in situ, and high signal-to-noise ratio. PLMs with tunable persistent luminescence and desired decay patterns are still required to meet the demands of multiple bioassays and time-resolved fluoroimmunoassays. Herein, persistent luminescence nanorods with distinct decay patterns are prepared by doping Mn2+, Mo6+, Cr3+, and Sr2+ in the Zn2GeO4 (ZGO) host material, and persistent luminescence nanoparticles are synthesized by doping Cr3+ in the ZnGa2O4 (ZGC) host material. Green-emitted ZGO:Mn NRs and NIR-emitted ZnGa2O4:Cr (ZGC) NPs show slow luminescence decay rates and noninterfered colors and are alternative probes for the dual detection of prostate specific antigens and carcinoembryonic antigens (CEAs). The limits of detection are as low as 8.9 fg mL–1 PSA and 72 fg mL–1 CEA. The nanoprobes are capable of monitoring the CEA level in the human serum matrix. This work provides a new window for the fabrication of multiplex colored PLMs with desired decay patterns, which were used in high throughput cancer early screening, cancer diagnostics, and time-resolved fluoroimmunoassay.

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An electrochemical sensing interface is limited by poor reproducibility and inevitable interferences present in practical applications due to the weak electrochemical signals of nanotags. This motivates the need for effective strategies to enhance the electroactivity performances of nanotags. In this contribution, a plasmon-enhanced electroactivity mechanism is proposed for AuRu-based nanostructures under illumination and applied for accurate detection of human epidermal growth factor receptor-2 (HER2). AuRu nanoparticles (NPs) harvested light energy through plasmon excitation and generated holes to participate in the electrooxidation process. The production of holes resulted in the electrooxidation signal enhancement of AuRu NPs. AuRu NPs were assembled with Au NPs using HER2 aptamers as linkers, and the plasmonic coupling between AuRu NPs and Au NPs produced an intense electromagnetic field, which further enhanced the electrooxidation signals of AuRu NPs. An AuRu–Au NP assembly-dependent electrochemical aptasensor was established for the accurate detection of HER2, and the limit of detection (LOD) was as low as 1.7 pg/mL. The plasmon-enhanced electroactivity mechanism endowed AuRu-based nanostructures with strong and noninterfering electrochemical signals for sensitive and accurate detection. This insight opens new horizons for the construction of desired electroactive nanostructures for electroanalysis applications.

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Electrochemical nanotags with controllable and multiresponse electroactivity have a great capacity for overcoming the drawbacks of limited target monitoring and inaccurate detection results for electrochemical sensors. In this contribution, double electro-oxidative Ru and Cu metals were integrated into RuCu nanostructures for the generation of dual electro-oxidative signals. A facial approach was proposed for the controllable fabrication of RuCu cage nanoparticles (NPs) and RuCu alloy NPs by simply adjusting the pH value of the reaction system. RuCu cage NPs and RuCu alloy NPs demonstrated inherent different electro-oxidative responses owing to the remarkable distinction of structures with different metal valences. RuCu cage NPs showed a single electro-oxidization peak at 0.84 V, assigned to the exposure of more Ru 0 electroactive sites on the hollow cage structures. RuCu alloy NPs illustrated dual electro-oxidization peak at 0.84 and −0.16 V, attributing to the presence of Ru 0 and Cu + electroactive sites on the alloy structures, respectively. RuCu cage NPs and RuCu alloy NPs served as specific electroactive tags, achieving the selective monitoring of Na 2 S and ratiometric electrochemical detection of xanthine in monosodium glutamate, respectively. The limits of detection were as low as 27 pM for Na 2 S and 70 nM for xanthine. The rational design of multimetal nanostructures holds enormous potential for the generation of multiresponse electroactivity with the impetus for exploring the capacity of specific electrochemical sensing.

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