The hysteretic properties of memristive silicon nanowires functionalized with these DNA aptamers provide a label-free and ultrasensitive biodetection technique. 
memristive silicon nanowires
Label-Free Ultrasensitive Memristive Aptasensor.We present the very first worldwide ever-reported electrochemical biosensor based on a memristive effect and DNA aptamers.  In this study, an affinity-based technique is presented for the detection of the prostate specific antigen (PSA) using DNA aptamers.  The hysteretic properties of memristive silicon nanowires functionalized with these DNA aptamers provide a label-free and ultrasensitive biodetection technique. 
DNA aptamers
The effect of polyelectrolytes on our memristive devices is also reported to further show how positive or negative charges affect the memristive hysteresis. 
polyelectrolytes