HPV 16 Signaling Probe Optimization. The HPV eSensor™ chip was decorated with 11 different HPV capture probes and an HIV capture probe as a negative control (shown in x-axis). An HPV 16 target mimic was detected by the eSensor in the presence of HPV 16 specific signaling probe (left panel) in which the sample also reacted with HPV 52-specific capture probe. The signal was identified as being from the hybridization between HPV 16 signal probe and the HPV 52 capture probe as shown in the mid-panel in which HPV 16 signal probe was introduced into the chip without any target mimic. The HPV 16 signal probe was modified replacing the second A base in the 5'-end with a G base. The resulted new signal probe hybridized specifically with the HPV 16 target mimic and did not cross-react with the HPV 52 capture probe.