Ultrasensitive electrochemical immunoassay for screening the influenza A (H1N1) virus based on atomically Ru-dispersed nitrogen-doped carbon

Abstract

Herein, a versatile electrochemical immunoassay was designed based on an atomically Ru-dispersed nitrogen-doped carbon (Ru–CN) modified disposable screen-printed carbon electrode (SPCE) for sensitive and specific screening of low-abundance influenza A (H1N1) virus with an innovative split-type strategy. Atomic-level Ru–CN can be obtained after pyrolysis of an acetylacetone ruthenium-encapsulated metal–organic framework (zeolite imidazolate framework 8, ZIF-8), which shows a good electrochemical response to ascorbic acid. To achieve H1N1 detection, an alkaline phosphatase (ALP)-loaded sandwich immunoassay was used to generate ascorbic acid in a 96-well plate, which is then dropped onto the Ru–CN modified disposable SPCE to generate a significant current signal using differential pulse voltammetry (DPV). Under optimal conditions, the DPV peak currents were positively correlated with the H1N1 influenza virus concentration in the dynamic working range of 1.0 ng mL⁻¹ to 10 000 ng mL⁻¹ with a limit of detection (LOD) of 0.28 ng mL⁻¹. During the detection of the H1N1 influenza virus, we also focused on the analysis performance of the sensor system and found that the platform has good reproducibility, high specificity, and acceptable stability. Impressively, the proposed sensing system is equivalent to the commercial detection method (ELISA) in the measurement of the H1N1 influenza virus from clinical samples, which further confirms the accuracy of the Ru–CN-based electrochemical immunoassay method. This enhanced analytical performance through atomic-level dispersed metals gives a new horizon to develop highly sensitive electrochemical immunoassays in the field of early detection of epidemic viruses.