Multi-analyte biosensors on a CF₄ plasma treated Nb ₂O₅-based membrane with an extended gate field effect transistor structure

Multianalyte biosensors were fabricated with an Nb₂O₅ pH-sensitive membrane on silicon substrate in an EGFET structure. Incorporation of CF₄ plasma treatment with an appropriate time of 15 s was found to improve material properties and enhance performance. Multiple material analyses including XRD, AFM and SIMS indicate that CF₄ plasma treatment reduces dangling bonds and passivates defects by forming strong bonds. Results indicate that an Nb₂O₅-based EGFET exhibited good performance with a high degree of sensitivity, a low hysteresis voltage and a low drift rate. Overall sensing performance for various ions of Na⁺, K⁺, urea and glucose detection was also enhanced. Our research indicates that Nb₂O₅-based biosensors with CF₄ treatment show promise for future industrial biosensing applications.