Fe-FeNn nanoparticles anchored bamboo-like morphology of N-doped graphitic carbon nitride nanotubes enabled electrochemical DNA-based biosensing of head and neck-squamous cell carcinoma miRNA-203

We describe a biosensing platform for the early screening of metastatic lymph nodes in patients with head and neck squamous-cell-carcinoma. The tunable iron nanoparticles (Fe-FeNn) inserted bamboo-like nanostructured N-doped carbon nanotubes (CNTs) obtained from a graphitic carbon nitride (GCN) are a source material for the highly sensitive detection of miRNA-203 in human serum and urine samples. The CNTs/GCN with tunable Fe precursors annealed at 900 °C enables the formation of Fe-FeNn nanoparticles (n = 0.5, 1.0, and 2.0 mmol of Fe) intercalated bamboo-like morphology of CNTs/GCN, which is denoted as Fe-FeNn/CNTs/GCN nanocomposite. Particularly, the bamboo-like nanotubes were derived from layered-structure of graphitic carbons with several voids and pores. The synthesized bamboo-like Fe-FeNn/CNTs/GCN was used to construct a biosensing platform through coordinate covalent bonding between Fe-FeNn and phosphate functionality of probe DNA. The developed bamboo-like Fe-FeNn/CNTs/GCN-based biosensing platform exhibited potential detection toward cancerous miRNA from 10 to 5000 fM with the limit of detection of 0.11 fM (S/N = 3). Under optimized conditions, the developed Fe-FeNn/CNTs/GCN biosensing platform was applied to detect miRNA in complexed biological fluids, such as human blood serum and saliva samples with satisfied recovery results (94.22%–97.40%).