An Internally\nAttached Aptameric Graphene Nanosensor\nfor Sensitive Vasopressin Measurement in Critical Patient Monitoring

This paper presents an aptameric graphene nanosensor\nfor rapid\nand sensitive measurement of arginine vasopressin (AVP) toward continuous\nmonitoring of critical care patients. The nanosensor is a field-effect\ntransistor (FET) with monolayer graphene as the conducting channel\nand is functionalized with a new custom-designed aptamer for specific\nAVP recognition. Binding between the aptamer and AVP induces a change\nin the carrier density in the graphene and resulting in measurable\nchanges in FET characteristics for determination of the AVP concentration.\nThe aptamer, based on the natural enantiomer D-deoxyribose, possess\noptimized kinetic binding properties and is attached at an internal\nposition to the graphene for enhanced sensitivity to low concentrations\nof AVP. Experimental results show that this aptameric graphene nanosensor\nis highly sensitive (with a limit of detection of 0.3 pM and a resolution\nof 0.1 pM) to AVP, and rapidly responsive (within 90 s) to both increasing\nand decreasing AVP concentration changes. The device is also reversable\n(within 4%), repeatable (within 4%) and reproducible (within 5%) in\nAVP measurements.