Rapid allele-specific hybridization chain reaction platform for portable GMO molecular marker detection

Overview

This solution offers a rapid, non-PCR molecular detection platform designed to identify GMO molecular markers directly from plant tissue. By combining pH-responsive chitosan-coated magnetic nanoparticles for in-situ nucleic acid extraction with an allele-specific hybridization chain reaction (HCR), the platform delivers sensitive genetic analysis without the need for traditional laboratory-based PCR equipment. The system is engineered for use with portable optical instruments, enabling point-and-shoot molecular diagnostics in field, agricultural, or resource-limited environments. The technology addresses a critical need in the agricultural biotechnology and regulatory compliance sectors for fast, deployable genetic screening tools.

Technical specifications

Key features:

• In-situ nucleic acid extraction: Chitosan-coated magnetic nanoparticles capture DNA from plant tissue lysates under acidic conditions; a higher-pH elution buffer releases purified DNA for downstream analysis.
• Allele-specific HCR amplification: Recombinant polymerase reactions generate small fragments complementary to allele-specific probes, triggering a catalytic DNAzyme-integrated hybridization chain reaction (patent pending).
• Colorimetric visual readout: DNAzyme sequences incorporated into hairpin structures produce a visual colorimetric signal, eliminating the need for advanced instrumentation to interpret results.
• Portable optical detection: Signal capture uses compact, portable optical devices, including a portable spectrometer validated in prior biomarker detection work.
• Prior analytical validation: The underlying HCR approach has detected cardiac troponin I at 0.5 pg/mL in patient samples and HCV-RNA at 100 fM, confirmed through transmission electron microscopy, gel electrophoresis, fluorescence quenching, UV-Vis spectrophotometry, and dynamic light scattering.
• Machine learning classification: Support vector machine (SVM) analysis of HCR results has achieved 95.33% accuracy in differentiating patient samples with high biomarker levels.

Technology readiness level

The platform is currently at an early-to-mid development stage. The core HCR and DNAzyme-based detection chemistry has been validated on human biomarkers (cardiac troponin I and HCV-RNA), demonstrating proof-of-concept for sensitivity and specificity. However, adaptation to plant tissue GMO marker detection is still pending. The proposed validation plan outlines two aims to be completed within one year: (1) demonstrating DNA extraction from plant tissue using chitosan-coated magnetic nanoparticles, and (2) implementing allele-specific HCR with DNAzyme-mediated colorimetric readout to differentiate wild-type and mutant sequences. Funding is sought for key personnel, custom DNA sequence synthesis and modification, and optical sensor materials. Upon completion of these aims, the technology will be positioned for pilot validation in agricultural settings.