Supramolecular DNA sensor based on the integration of host-guest immobilization strategy and WP5-Ag/PEHA supramolecular aggregates

Primary liver cancer, mostly hepatocellular carcinoma (HCC) is the most common cause of cancer-related deaths around the world. Hepatitis B virus (HBV) DNA is the dominant factor that influences the progression of HCC. In this work, a novel electrochemical sensor triggered by a sandwich hybridization reaction has been developed for the ultrasensitive detection of HBV DNA. The multi-walled carbon nanotubes (MWCNTs) and hydroxylatopillar [5]arene (HP5) stabilized Au nanoparticles are used to modify the electrode to immobilize Rhodamine B-labeled DNA probes and improve the electron transfer efficiency. A supramolecular aggregate was synthesized based on pentaethylenehexamine (PEHA) induced self-assembly behavior of water-soluble pillar [5]arene (WP5) stabilized Ag nanoparticles through host-guest interaction, which serves as signal materials. The sensitivity of the sensor has enhanced on account of the electrochemical oxidation from Ag to Ag+ to yield an electrochemical response greater than that of the single silver nanoparticle. Linear sweep voltammetry (LSV) curves illustrate that the response has a good linear relationship with the logarithm of HBV-DNA concentration in a wide range from 0.1 fmol/L to 0.1 nmol/L, and the detection limit is 0.19 fmol/L according to the 3σ rule. Besides, the sensor shows good reproducibility, stability and selectivity, providing a promising prospect for application in disease diagnosis and prognosis.