Research PaperQuenched solid-state electrochemiluminescence of gold nanoclusters and the application in the ultrasensitive detection of concanavalin A

- This work investigated the quenching effect of Fc-COOH towards Au25-Et3N ECL system and the detailed quenching mechanism was investigated.
- We focus on a facile synthesis of PtPd NCs and make them serve as a promising carrier for high loading of the quencher Fc-COOH.
- The ECL biosensor showed a wide linear range from 0.004 ng/mL to 90 ng/mL and a low detection limit of 0.001 ng/mL for ConA detection.

This work investigated the quenching effect of ferrocenecarboxylic acid (Fc-COOH) on the bovine serum albumin-stabilized Au nanoclusters-triethylamine (Au25-Et3N) electrochemiluminescence (ECL) system. Based on the annihilation between the oxidation product of Fc (Fc+) and Et3N radical, a quenching-based sandwich-configuration ECL biosensor was established for sensitive and specific detection of concanavalin A (ConA). Au25 with strong initial ECL signal were modified onto the glassy carbon electrode (GCE) for immobilizing glucose oxidase (GOD). With the further immobilization of target ConA, the quenching probe of GOD@Fc-COOH-PtPd nanocubes were incubated onto the electrode through a specific carbohydrate-ConA interaction, thus achieving a sandwich structure. The resulting ECL biosensor showed a wide linear range from 0.004 ng/mL to 90 ng/mL and a low detection limit of 0.001 ng/mL (S/N = 3) for ConA detection. The integration of Fc-COOH with Au25-Et3N system would hold a great promise in bioanalysis.

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