Nanostructured interface-engineered field-effect transistor biosensors for sensitive detection of serum miRNAs

<p>The efficient detection of disease-relevant biomolecules in untreated clinical samples is highly desired, especially for acute diseases. Field-effect transistor (FET) biosensors allow label-free and rapid detection of biomolecules through the measurement of their intrinsic charges. However, the sensitivity of FET biosensors would be undermined by the charge screening effect in practical biological media with high ionic strength. Here, we report the design and performance of a nanostructured interface-engineered field effect transistor (NIE FET) biosensor for highly sensitive detection of cardiovascular disease (CVD)-associated miRNAs in serum samples. Molecular dynamic simulations and electrochemical characterizations demonstrate that the nanostructured interface with concave regions alleviates the charge screening effect and enlarges the Debye length. The rationally designed NIE FET biosensor exhibits high sensitivity and reproducibility in detecting miRNA in untreated serum samples with a detection limit of pM level. Benefiting from its excellent detection capabilities, NIE FET reveals the relationship between miRNAs and CVDs and realizes the effective classification of different CVD types with the help of machine learning algorithms. The construction of NIE FET defines a robust strategy for electrical biomolecular detection in practical clinical samples.</p>