Palm-Sized Device Detects Disease-Related Genetic Material In 45 Minutes

Polymerase chain reaction (PCR) and real-time immunoassays are widely used for accurate diagnostics, but they come with key limitations. Their dependence on time-intensive processes, costly thermal cyclers, and trained personnel makes them impractical for rapid outbreak response, early cancer detection, or bedside use, especially in low-resource environments. To address these barriers, researchers have introduced a compact, palm-sized device that bypasses conventional amplification steps and directly converts biological signals into detectable DNA fragments using a tandem nuclease cascade.

Developed by scientists from the National University of Singapore (NUS, Singapore), this innovative platform is called NAPTUNE—short for Nucleic Acids and Protein biomarkers Testing via Ultra-sensitive Nucleases Escalation. The system was designed as a true point-of-care assay that can detect extremely low levels of nucleic acid and protein disease markers in under 45 minutes. According to findings published in Nature Communications, it eliminates the need for laboratory infrastructure or complex sample preparation. NAPTUNE operates using a two-stage enzymatic cascade. The first stage leverages APE1, a human DNA-repair enzyme, to identify abasic (AP) sites engineered within a reporter duplex. This enzyme cleaves the duplex and releases 5′-phosphorylated DNA guide strands. In the second stage, these DNA guides activate a heat-stable Argonaute protein derived from Pyrococcus furiosus (PfAgo), which then cleaves fluorophore-quencher probes in a chain reaction. The resulting fluorescence is directly proportional to the concentration of the disease target.

This enzymatic relay system dramatically enhances detection sensitivity—from the femtomolar range achievable by APE1 alone to the attomolar (10⁻¹⁸ M) range—establishing a new standard for amplification-free detection. To ensure the technology’s portability and ease of use, the researchers miniaturized the NAPTUNE assay into a single-use tube equipped with a battery-powered heater and Bluetooth-enabled fluorescence reader. Weighing less than 200 grams, the device streams real-time diagnostic results to a mobile application, making it suitable for virus tracking, cancer screening, and other clinical uses outside traditional labs. Currently, the NUS team is validating the NAPTUNE platform for tuberculosis detection using sputum samples. They are also exploring lyophilized reagent kits that can withstand tropical climates, and working on additional formats such as electrochemical and lateral-flow readouts. These efforts aim to accelerate the tool’s commercial rollout and broaden its application in decentralized diagnostics worldwide.

“By chaining two naturally occurring nucleases in an orthogonal circuit, we achieve PCR-class sensitivity without touching a thermocycler,” said NUS Assistant Professor Chunyi HU. “Our vision is to place laboratory-grade diagnostics directly into the hands of community health workers.”

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