Multi-analyte biosensors on a CF4 plasma treated Nb2O5-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.