Smartphone-based colorimetric point-of-care system for GMO DNA/RNA detection

Overview

This technology addresses the need for rapid, low-cost, and field-deployable detection of GMO DNA/RNA and microRNA targets. Conventional laboratory-based PCR methods are time-consuming, expensive, and require trained operators and specialized equipment. The proposed solution combines plasmonic nanoparticle-based colorimetric assays with smartphone-powered artificial intelligence to deliver a simple, portable, multiplex, and quantitative point-of-care detection platform. The system is designed for routine use by minimally trained personnel at the point of need under field conditions, with particular relevance for assessing the genetic quality of leaf and seed materials in agricultural and regulatory settings.

Technical specifications

Core technology components:

• A smartphone equipped with a 3D-printed optical accessory and a custom-built application for automated image acquisition, processing, result display, and data storage
• A colorimetric assay called Plasmonic Coupling Interference (PCI) that uses silver nanoparticle-based nanoprobe constructs (probe-A and probe-B) designed for specific nucleic acid sequences
• Target nucleic acids act as competitors that interfere with nanoparticle aggregation, producing measurable color changes linked to target concentration
• Multiplex detection capability enabled by using different nanoparticle types (silver or gold nanospheres, nanorods, nanostars) with distinct plasmonic absorption bands and colors
• An onboard AI processor using convolutional neural network-based machine learning to interpret individual target signals and deliver automated results
• Amplification-free workflow, eliminating the need for PCR or other nucleic acid amplification steps

The system has been validated to provide quantitative estimations comparable to a laboratory-based spectrophotometer when measuring microRNA biomarkers.

Technology readiness level

The Krometriks smartphone biosensing device has been built and demonstrated for colorimetric microRNA detection with accuracy comparable to lab-based spectrophotometers. The proposed next phase focuses on adapting the PCI assay for multiplex GMO DNA/RNA detection by optimizing nanoprobe sensitivity, dynamic range, specificity, and limit of detection. A second-generation AI-powered device will be fabricated, followed by technical evaluation to detect DNA/RNA targets directly in plant materials with minimal or no purification. The platform is advancing toward a fully integrated sample-to-answer system suitable for routine field deployment.