Integration and bio-functionalization of vertically aligned carbon nanotube forests on high frequency AlN gravimetric sensors

Abstract

In this work, we grow different types of carbon nanotube (CNT) forests directly on AlNbased electroacoustic biosensors and study their functionalization efficiency. CNTs are used to increase the effective surface area of the sensor, pursuing a better sensitivity, without increasing the sensor capacitance. Here we use a general method for CNT bio-functionalization with specific receptors for targeted species. First, we make them hydrophilic. Next, we cover them with alternating polymers. Finally, we incubate their surface in an N-hydroxysuccinimide biotin solution. To study the functionalization homogeneity along the CNT length, Streptavidin conjugated with fluorescein isothiocyanate is used as the targeted species for confocal fluorescence microscopy characterization.