Eco-Friendly Engineered Ternary Nanocomposite for Label-Free Fluorescent SARS-CoV‑2 N‑Gene DNA Detection

Area of Science:

• Biomaterials Science
• Nanotechnology
• Molecular Diagnostics

Background:

• The COVID-19 pandemic highlighted the need for rapid, scalable nucleic acid sensing platforms for point-of-care applications.
• Existing platforms often face limitations in speed, resilience, and integration.

Purpose of the Study:

• To develop a green-engineered fluorescence biosensing platform utilizing a novel ternary nanocomposite.
• To functionalize the nanocomposite for specific detection of SARS-CoV-2 genetic material.
• To evaluate the platform's performance in detecting target DNA at low concentrations.

Main Methods:

• Fabrication of a silver-titanium dioxide-cerium oxide (Ag-TiO2-CeO2) ternary nanocomposite using Morinda citrifolia leaf extract.
• Functionalization of the nanocomposite with antisense probes targeting the SARS-CoV-2 N-gene.
• Enzyme-free hybridization assays using synthetic and human genomic DNA as targets.

Main Results:

• The green-synthesized nanocomposite exhibited biocompatibility, high surface area, and oxygen vacancies favorable for nucleic acid interaction.
• The biosensing platform demonstrated a significant fluorescence shift within 30 minutes of hybridization.
• The platform achieved a detection limit of 3 pM for unlabeled target DNA.

Conclusions:

• The developed nanocomposite fluorescence biosensing platform shows promise for sensitive and rapid nucleic acid detection.
• The material proof-of-concept paves the way for advanced viral diagnostics in complex biological samples.
• This green-engineered approach offers a sustainable and efficient method for developing point-of-care diagnostic tools.