Aptameric Metal-Organic Framework Nanobiosensor

An affinity nanobiosensor is presented that uses an aptamer-functionalized Ni₃(HITP)₂ metal-organic framework (MOF). The device is a field-effect transistor (FET) with the MOF as the conducting channel and is functionalized with an aptamer for specific biomarker recognition. Binding between the aptamer and the target biomarker induces a change in the carrier density in the MOF, resulting in measurable changes in FET characteristics for determination of the biomarker concentration. In situ synthesis of the MOF enhances the adhesion between the MOF film and electrodes to reduce noise during sensor operations while also allowing devices to be potentially mass-producible at a reduced cost. Thanks to the porous structure of the MOF, the aptamer surface density on the MOF is optimized to enhance sensitivity for biomarker measurements. Experimental results show that the MOF nanobiosensor is capable of reliable and sensitive measurements of tumor necrosis factor α (TNF-α) with a responsivity of 0.38 mV/pM and a limit of detection of 8.7 pM, which are 2.7 times the responsivity and 34% of the limit of detection of a comparison aptameric sensor that used manually transferred graphene as a transduction material.