A biomimetic AuNPs@MBene-TFT artificial tongue for sensitive non-invasive salivary microRNA-27a detection in HNSCC assessment

Head and neck squamous cell carcinoma (HNSCC) remains a major clinical challenge, highlighting the need for sensitive and non-invasive salivary biomarker detection strategies. Salivary microRNA-27a is a promising biomarker candidate, but its practical detection is limited by the sensitivity and integration of current platforms. Herein, we developed a biomimetic artificial tongue based on AuNPs@MBene-functionalized thin-film transistors (TFTs) for sensitive salivary microRNA-27a detection. The AuNPs@MBene nanocomposite was synthesized via a hydrothermal method, with gold nanoparticles decorated on layered MBene to provide a nanostructured interface for probe immobilization and signal transduction. After optimization of DNA capture probe concentration, incubation time, pH, and temperature, the optimal conditions were determined as 40 μM, 30 min, pH 7.0, and 37 °C, respectively. The device showed good stability, with only 1.12% signal decay after 30 days, and high reproducibility, with a batch-to-batch relative standard deviation of 1.21%. It achieved a linear detection range from 10 fM to 1 nM, with R 2 = 0.9886 and a limit of detection of 3.2 fM. A 64-channel array was further constructed for spatially resolved and time-dependent target monitoring. In a preliminary clinical evaluation, the platform distinguished saliva samples from 11 healthy controls and 13 HNSCC patients, with p = 0.00027 and an AUC of 0.901. These results demonstrate the potential of the AuNPs@MBene-TFT artificial tongue for non-invasive salivary microRNA detection and HNSCC-associated biomarker analysis.