A preprint posted to arXiv (arXiv:2603.23775) describes a novel signal detection approach called 'interfacial potential transduction' that researchers say could overcome longstanding limitations of both optical and electrochemical diagnostic methods used in portable medical testing devices.

Current point-of-care diagnostics face a persistent trade-off: optical readouts — such as those used in standard lateral flow tests — require supporting instruments and are difficult to miniaturize, while compact electrochemical sensors are vulnerable to interference from biological fluids like blood plasma, which can distort results and limit what biomarkers can be reliably measured outside a clinical laboratory.

The research team proposes interfacial potential transduction as a standardized electrical modality designed to work across multiple assay formats while controlling for signal distortion caused by biological sample matrices. Their mechanistic framework identifies key parameters within the transduction system that allow researchers to account for interference from complex biofluids.

In demonstration experiments, the method was applied to a lateral flow immunoassay format — the same basic platform used in home COVID-19 tests — to quantitatively detect three reproductive hormones: estradiol, progesterone, and luteinizing hormone, in human plasma samples. The team reported high correlation (r² > 0.97) with results from established clinical analyzers, suggesting analytical precision comparable to hospital-grade equipment.

The researchers also demonstrated the approach across several other diagnostic categories. For blood glucose measurement, they reported a limit of detection of 0.92 micrograms per deciliter. For HIV detection, the system detected the p24 capsid protein — a key early marker of HIV infection — at a concentration of 44.8 femtograms per milliliter using an immunomagnetic separation workflow. The team also reported detection of hepatitis B virus within five minutes using a molecular amplification technique called loop-mediated isothermal amplification (LAMP).

The authors argue these results, spanning biochemical, immunological, and molecular diagnostic categories, establish interfacial potential transduction as a 'unified diagnostic paradigm' for near-patient deployment.

Important caveats apply. This work is a preprint, meaning it has not yet undergone peer review, and independent validation of the reported performance figures has not been conducted. Sample sizes and full clinical validation details are not disclosed in the abstract. The study does not report how the method performs across varied patient populations or in field conditions outside a controlled laboratory environment. Regulatory approval for any device based on this method would require extensive additional testing.

Source: https://arxiv.org/abs/2603.23775