A pyro-electrohydrodynamic approach for detecting low abundant pathological biomarkers

The detailed molecular insight is particularly important because even minor structural modifications in proteins, such as Tau, amyloid or synuclein family, are closely linked to the initiation and progression of neurodegenerative disorders, thereby making them critical targets for early diagnostic efforts. In the context of extended space missions, where long-term monitoring is crucial, our innovative approach could prove invaluable for tracking astronauts’ health, with the introduction of the pyro-electrohydrodynamic jetting (p-jet) technique. This method exploits a combination of thermal and electrical forces to accurately deposit and concentrate biomolecules onto chemically treated surfaces. Here we demonstrate that p-jet technology can effectively concentrate highly diluted biomolecules into distinct fluorescent micro-spots on a reactive substrate, confirming its potential as a powerful tool in biosensing. One of the key challenges addressed here is to enhance the binding efficiency of low-abundance proteins to improve the detection sensitivity. To this end, we used bovine serum albumin (BSA) as a model protein to evaluate its immobilization within the p-jet spots. Our results revealed that, especially when covalent bonding is employed, the p-jet method produces a reliable, concentration-dependent signal, achieving an impressive limit of detection (LOD) of 4.5fM—far surpassing the sensitivity of standard ELISA techniques. Taking a step further towards clinical applications, we applied the p-jet technique to detect pre-aggregated Tau protein in artificial urine, which mimics human biological fluids. This approach allowed us to detect Tau at femtomolar concentrations (LOD of 130 fM) while preserving its structural integrity. With its minimal sample requirements and cost-effective nature, this p-jet technique marks an advancement in the early monitoring of neurodegenerative syndromes, with significant potential for diverse point-of-care (POC) scenarios. It could also play a key role in contexts such as long-term human space exploration missions, where early diagnosis of neurodegeneration is crucial.