Nanoparticle-based point-of-care testing tool for multiplex DNA/RNA detection in plant materials

Overview

This research program is developing a point-of-care testing (POCT) platform for multiplex DNA and RNA detection in plant materials, with a particular focus on identifying genetically modified organisms (GMOs). The platform is built on gold nanoparticle (GNP) technology and is being pursued through two parallel approaches: an electrochemical biosensor using screen-printed electrodes and a paper-based biosensor using thin-layer chromatography. Both formats are designed to be miniaturized, user-friendly, and operable in field settings by non-expert staff, addressing the need for rapid genetic quality assessment outside of laboratory environments. The program is led from Prof. Michael Thompson's lab at the University of Toronto, with collaboration across surface chemistry, electrochemistry, and biosensing expertise.

Technical specifications

Core technology components:

• Gold nanoparticle-based detection using two complementary platforms—electrochemical (screen-printed electrodes with a portable potentiostat) and paper-based (thin-layer chromatography)
• DNA probes as biorecognition elements, enabling inherent specificity and the capacity for multiplex sensor design to identify multiple targets simultaneously, including GMO markers
• Novel dithiol linker for gold surface modification that exhibits exceptional antifouling properties, reducing non-specific adsorption and enhancing both sensitivity and selectivity
• Surface chemistry expertise drawn from prior work in antifouling surface design, acoustic wave technology, and electrochemical biosensor development
• Projected performance: up to 20 samples processed within a 2-hour timeframe
• Comparative evaluation of the two platforms to establish the optimal approach for on-field genetic quality assessment

Technology readiness level

The project is at an early-to-mid stage of development, supported by substantial preliminary evidence. Prior work has demonstrated selective electrochemical detection of CTV nucleic acids in plant samples, differentiation of GMO soybeans without complex cleaning procedures, and significant reduction of non-specific adsorption using the novel dithiol linker on gold surfaces validated through electrochemical and acoustic wave platforms. A clinical diagnostics electrochemical biosensor incorporating this linker has also shown reduced fouling and enhanced sensitivity. The feasibility of the proposed POCT concept is further supported by commercial precedents such as glucose meters (electrochemical) and COVID-19 rapid tests (paper-based). The upcoming year-long validation phase will optimize GNP modification with dithiol linkers, fabricate and test both biosensor formats, and compare their performance for simultaneous DNA/RNA detection in plant materials.