Development of a Gold Nanoparticle-Based Amplification-Free Nanobiosensor for Rapid DNA Detection Supported by...

Area of Science:

• Nanotechnology
• Biosensing
• Molecular Diagnostics

Background:

• Growing global genetically modified (GM) crop cultivation necessitates advanced analytical tools for detection.
• Conventional methods like PCR are sensitive but require complex equipment and expertise, limiting field use.

Purpose of the Study:

• To develop a rapid, cost-effective, label-free, and amplification-free nanobiosensor for GM DNA detection.
• To enable on-site screening of GM ingredients, aiding traceability and regulatory compliance.

Main Methods:

• Utilized citrate-capped gold nanoparticles (AuNPs) and localized surface plasmon resonance (LSPR) for colorimetric detection.
• Developed an assay for direct detection of the Cry1Ac gene without PCR or enzymatic amplification.
• Integrated a Support Vector Machine (SVM) algorithm for automated spectral classification and semi-quantitative analysis.

Main Results:

• Achieved direct colorimetric detection of the Cry1Ac gene via AuNP aggregation and LSPR shift.
• Optimized reaction parameters (NaCl concentration, AuNP size, ionic strength) for selectivity and reproducibility.
• Demonstrated high sensitivity (LOD ≈ 2.5 ng μL⁻¹), specificity, and classification accuracy (>90%) using the AuNP-SVM system.

Conclusions:

• The proposed AuNP-SVM nanobiosensor provides a simplified, rapid, and cost-effective alternative for on-site GMO screening.
• Elimination of amplification steps reduces assay time, complexity, and instrumentation needs.
• The platform is suitable for field applications, supporting accurate GM ingredient detection and labeling.