N/S co-doped carbon dots-based solution-gated graphene transistors (SGGT) for ultra-sensitive and selective determination of Hg (II) ions in real water and serum samples

• Published in: Microchemical journal 2024-06, Vol.201, p.110626, Article 110626
• Main Authors: Xue, Chenglong, Ren, Zhanpeng, Wang, Jianying, Deng, Minghua, Li, Jiashen, Wang, Xianbao, Li, Jinhua
• Format: Article
• Language: English
• Subjects: Carbon dots; Detection; Hg2+ ions; Sensitivity; SGGT
• ISSN: 0026-265X
• DOI: 10.1016/j.microc.2024.110626

[Display omitted] •A novel SGGT sensor is constructed for highly sensitive detection of Hg2+ ions.•N/S co-doped carbon dots modify the gate electrode as the recognition probes.•Ultralow LOD (0.1 fM) and rapid detection time (∼40 s) can be achieved.•The real water and serum samples can be detected by using SGGT sensor. The conventional methods for detecting Hg2+ ions are generally impaired by low sensitivity, a high limit of detection (LOD), and the long detection time required. In this work, we develop a novel solution gated graphene transistor (SGGT) based on carbon dots doped with N and S elements (N/S CDs) as gate electrode probes. The prepared N/S CDs, which are 3–5 nm in diameter, are first modified at the gate of the SGGT through covalent bonding that specifically recognizes Hg2+ ions. The SGGT is then used as a Hg2+ sensor, exhibiting good selectivity, ultrahigh sensitivity, good reproducibility, and a short detection time. The SGGT sensor has an excellent linear detection range, from 0.1 fM to 1 nM. The LOD can reach 28 aM, which is far lower than that of conventional detection methods. Moreover, the SGGT sensor also has a rapid response time of ∼ 40 s. Finally, the ability to analyze real water samples and serum samples is demonstrated.