Low-cost electrochemical CRISPR biosensor for point-of-care DNA/RNA detection

Overview

This solution is a point-of-care nucleic acid detection system designed to bring laboratory-grade genotyping capability directly to the field. Built on CRISPR-based biosensing chemistry paired with low-cost electrochemical sensors, the platform enables amplification-free detection of single nucleotide polymorphisms (SNPs), deletions, and insertions in genomic DNA extracted from plant leaves and seeds. The system targets agricultural diagnostics where rapid, inexpensive, and scalable testing is needed. Each test is designed to cost less than 20 cents and deliver results in under 10 minutes, making high-throughput genotyping economically feasible. A compact portable reader connects to a smartphone app that automatically uploads results to the cloud for remote viewing.

Technical specifications

• CRISPR enzyme chemistry: Leverages Cas12a (for DNA targets) and Cas13 (for RNA targets) enzymes activated by guide RNA-target binding, triggering collateral cleavage of redox-labeled reporter molecules.
• Electrochemical sensor: Low-cost, mass-produced screen-printed three-electrode strip with a working electrode modified with graphene and a PEG-DNA/RNA reporter hydrogel containing ferrocene-labeled reporters.
• Detection mechanism: Activated Cas enzyme cleaves hydrogel-bound ferrocene reporters, generating an amperometric signal measurable by a miniaturized potentiostat.
• Sensitivity: Picomolar limit of detection achieved without nucleic acid amplification, based on validated catalytic efficiencies of 10⁵–10⁶ M⁻¹s⁻¹ for multiple Cas12 and Cas13 orthologs.
• Sample preparation: Compatible with standard rapid extraction methods such as Zymo Research's Quick-DNA Plant/Seed kit for leaf and seed DNA.
• Hardware: Small, portable electronics board housed in customizable enclosure, paired with an Android mobile app featuring cloud-enabled result sharing.
• Cost structure: Screen-printed plastic strips manufactured at scale; total per-test cost targeted below 20 cents.

Technology readiness level

The underlying CRISPR kinetic parameters and amplification-free detection limits have been characterized and published. The electrochemical sensor platform, including screen-printed electrodes, nanomaterial and enzyme modifications, and portable electronics, has been validated through Zethea's first commercial product line in glucose monitoring. Translation of the sensor chemistry from fluorescent to electrochemical reporters for nucleic acid detection has begun and is currently in early-stage testing. Remaining development includes optimization of the full integrated system—reagent kit, biosensor, miniaturized potentiostat, and smartphone app—for in-field agricultural diagnostics. The team is actively seeking a co-development partner to match funding and resources needed to complete validation and commercialization.