We developed an Yb2Ti2O7-electrolyte-insulator-semiconductor (EIS) biosensor that can rapidly discriminate clinical statuses of prostate cancer (PCa) by detecting the existence of androgen-receptor splice variant 7 (AR-V7) messenger RNA. The structural feature of YbTixOy sensing membranes anneal to Si substrates through reactive cosputtering with different annealing temperatures investigated. Results showed annealed at 900 degrees C exhibited higher sensitivity of 61.11 mV/pH, lower hysteresis voltage of 1.6 mV, and smaller drift rate of 0.16 mV/hr. This attributed to the well-crystallized Yb2Ti2O7 structure, detected using X-ray diffraction and X-ray photoelectron spectroscopy. We then compared two different methods, encapsulating or covalently bonding of the probe, to detect existence of AR-V7 in PCa. After hybridization of the probe with the target cDNA sequence, the covalent binding of AR-V7 probe method exhibited a larger V-REF shift in the capacitance-voltage curves for the detection of AR-V7. Furthermore, highly reliable and stable results (>95% repetition rate) also could be observed when compared to that encapsulated probe on the EIS. Our data demonstrated this AR-V7 probe-based Yb2Ti2O7-EIS biosensor is a rapid, simple, label-free, economical, and accurate diagnostic device, and provide fast identification of resistant statuses in circulating tumor cells of PCa, essential for clinicians to make defining decisions. (C) 2016 The Electrochemical Society. All rights reserved.