Epitaxial Graphene Sensors Combined with 3D-Printed Microfluidic Chip for Heavy Metals Detection

Sensors

Donatella Puglisi¹  MariaFrancesca Santangelo¹  Jens Eriksson¹  Mikhail Vagin²  Daniel Filippini³  Rositsa Yakimova⁴  Ivan Shtepliuk⁴ 

[1] Applied Sensors Science, Department of Physics, Chemistry, and Biology-IFM, Linköping University, S-58183 Linköping, Sweden;Division of Physics and Electronics, Department of Science and Technology, Physics and Electronics-ITN, Linköping University, SE-58183 Linköping, Sweden;Optical Devices Laboratory, Department of Physics, Chemistry, and Biology-IFM, Linköping University, S-58183 Linköping, Sweden;Semiconductor Materials, Department of Physics, Chemistry, and Biology-IFM, Linköping University, S-58183 Linköping, Sweden;

关键词: heavy metals detection;    epitaxial graphene;    high sensitivity;    3D-printed flow cell;    reusable lab-on-chip;   

DOI  :  10.3390/s19102393

来源: DOAJ

【 摘 要 】

In this work, we investigated the sensing performance of epitaxial graphene on Si-face 4H-SiC (EG/SiC) for liquid-phase detection of heavy metals (e.g., Pb and Cd), showing fast and stable response and low detection limit. The sensing platform proposed includes 3D-printed microfluidic devices, which incorporate all features required to connect and execute lab-on-chip (LOC) functions. The obtained results indicate that EG exhibits excellent sensing activity towards Pb and Cd ions. Several concentrations of Pb²⁺ solutions, ranging from 125 nM to 500 µM, were analyzed showing Langmuir correlation between signal and Pb²⁺ concentrations, good stability, and reproducibility over time. Upon the simultaneous presence of both metals, sensor response is dominated by Pb²⁺ rather than Cd²⁺ ions. To explain the sensing mechanisms and difference in adsorption behavior of Pb²⁺ and Cd²⁺ ions on EG in water-based solutions, we performed van-der-Waals (vdW)-corrected density functional theory (DFT) calculations and non-covalent interaction (NCI) analysis, extended charge decomposition analysis (ECDA), and topological analysis. We demonstrated that Pb²⁺ and Cd²⁺ ions act as electron-acceptors, enhancing hole conductivity of EG, due to charge transfer from graphene to metal ions, and Pb²⁺ ions have preferential ability to binding with graphene over cadmium. Electrochemical measurements confirmed the conductometric results, which additionally indicate that EG is more sensitive to lead than to cadmium.

【 授权许可】

Unknown