One-pot synthesized AuNPs/MoS2/rGO nanocomposite as sensitive electrochemical aptasensing platform for nucleolin detection

Abstract

Simple, rapid, sensitive, and specific detection of cancer cells plays a pivotal role in the diagnosis and prognosis of cancer. This paper describes an alternative method for detection of nucleolin, which is a major nucleolar protein, overexpressed in several types of cancer, and is a cancer-specific target. Gold nanoparticles/molybdenum disulfide/reduced graphene oxide (AuNPs/MoS2/rGO) was easily synthesized with hydrothermal method and characterized by transmission electron microscopy (TEM), x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS). Combining the properties of large surface area and good electrical conductivity of AuNPs/MoS2/rGO with the high affinity and specificity of aptamer, a smart hierarchically self-assembled electrochemical aptasensor was established for the specific and sensitive nucleolin (as a model analyte) detection. Under the optimized conditions, AuNPs/MoS2/rGO based aptasensor exhibits a great performance for the detection of nucleolin with a linear response from 0.5 nM to 1.0 μM and a low detection limit of 0.16 nM. In addition, this electrochemical aptasensor has good reproducibility towards nucleolin. Besides, the practicability of the TNA (thiolated nucleolin aptamer)/AuNPs/MoS2/rGO was demonstrated by analysis of nucleolin in the blood sample. This work paves a promising way for the facile synthesis and design MoS2/rGO nanocomposite-based electrochemical aptasensor for testing tumor markers in clinical diagnostics.