A novel strategy for construction of a ratio dual signal electrochemical sensing platform to detect homocysteine

Reliable and selective sensing of homocysteine (Hcy) is essential for early screening and prevention of chronic diseases in elderly populations. In this work, we proposed a new " on-off " signal ratio sensing strategy. Specifically, homocysteine (Hcy) and catechol (Cat) were chosen as dual-signal probes, and the ratio sensing perform of Hcy was constructed by monitoring the dynamic changes of I_4-SH-Cat/I_Cat and I_Hcy/I_Cat. The linear response range covered 5.76 × 10^-⁹ ∼ 1.23 × 10^-⁴ M, with a low detection limit of 1.92 nM. Furthermore, the electrochemical reaction mechanism was explored thoroughly based on 1,4-Michael addition reaction between Hcy and Cat. Importantly, the proposed ratio electrochemical method can selectively identify Hcy in the presence of cysteine (Cys). Therefore, the study provides an effective method for realizing fast, reliable and sensitive determination of Hcy, and exhibits significant application value in biomedical analysis and clinical diagnosis for early screening of Hcy-related diseases.