Lamp-based biosensors for point-of-care GMO detection in crops

Overview

This solution addresses the need for rapid, affordable, and field-deployable detection of genetically modified organisms (GMOs) in major crops such as maize, soybean, wheat, and rapeseed. Traditional GMO testing relies on protein-based assays or quantitative PCR (qPCR), both of which require laboratory infrastructure, expensive equipment, and trained personnel. The proposed platform replaces these constraints with a point-of-care (POC) workflow that combines loop-mediated isothermal amplification (LAMP) of transgene sequences with novel electrochemical and field-effect transistor (FET)-based biosensors. The result is a detection system designed to deliver results in under 30 minutes without the need for sophisticated laboratory settings, making GMO screening more accessible to regulators, seed producers, food processors, and agricultural stakeholders.

Technical specifications

Core technology components:

• LAMP assays targeting vector and regulatory elements commonly used in GM constructs, including the CaMV35S, tNOS, and FMV35S promoters, enabling broad GMO screening
• Custom-designed LAMP primers optimized for speed (under 30 minutes) and specificity for POC use when existing literature primers are unsuitable
• POC-applicable DNA extraction protocols validated for both leaf and seed tissue of soybean and maize
• Electrochemical biosensors built on gold PVD (Physical Vapor Deposition) electrodes with pretreated surfaces, functionalized with single-stranded DNA probes at a density of approximately 600 pmol/cm²
• Redox-labeled DNA probes for signal generation, with detection tested via AC voltammetry and Electrochemical Impedance Spectroscopy (EIS)
• FET-based biosensors under development, assembled using advanced 2D nanomaterials such as graphene, reduced graphene oxide, crumpled graphene, MXenes, and transition metal dichalcogenides (TMDCs) to enhance sensitivity, selectivity, and measurement repeatability
• Dual detection strategy: direct detection of LAMP amplicons and indirect detection of unused LAMP primers as an indicator of reaction outcome
• Validation using synthetic gBlocks (TgBs) spiked into crude DNA extracts to simulate GMO targets in real-world sample matrices

Technology readiness level

The project is at an early-to-mid stage of development. To date, the team has completed DNA extraction protocol optimization for soybean and maize, designed specific single-stranded DNA probes, established electrode pretreatment protocols, and demonstrated probe immobilization on gold electrodes. Initial electrochemical testing using AC voltammetry has shown weak signals for single-stranded LAMP amplicons, while double-stranded amplicons did not hybridize with the surface-bound probes as expected. Ongoing work focuses on improving signal strength through EIS-based detection and developing the FET-based sensor platform using 2D nanomaterials. Future validation will involve testing sensor prototypes with synthetic GMO targets spiked into crude extracts, followed by broader validation across the four target crops. The technology is currently at a laboratory proof-of-concept stage and is not yet commercially ready.