Electrochemical Sensor Based on Biomass Yeast Integrated Sulfur-doped Graphene and Carboxylated Carbon Nanotubes/MoS2 for Highly-sensitive Detection of Pb2+

Abstract

Glassy carbon electrodes (GCEs) modified with sulfur-doped graphene (SG)/carboxylated carbon nanotube (CNT−COOH)/MoS2/yeast composite were prepared for electrochemical detection for lead ions by the simple hydrothermal methods and ultrasonic methods. The combination of SG and CNT−COOH could form a double-layer carbon structure, providing more active detection sites for detection for lead, which could also contribute to adherence of yeast and MoS2. The SG/CNT−COOH/MoS2/yeast exhibited a high response in detecting low concentrations of lead ions. And then the SG/CNT−COOH/MoS2/yeast was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Transmission electron microscope (TEM), Scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Compared with traditional detection technology, the linear range of the sensor was 10−6∼10−14 g/L. And the lower of detection (LOD) down to 2.61×10−15 g/L was achieved. The sensor showed prospective applications in detection of Pb2+ in real serum samples.