Plasma-enhanced surface modification of sprayed carbon nanotube electrodes for lithographically integrated biosensing system

A sprayed carbon nanotube (CNT)-modified working electrode was successfully integrated into an electrochemical three-electrode system based on a glass substrate. The integrated biosensing system was fabricated through a series of photolithographic patterning and plasma etching processes. A CNT-dispersed solution was sprayed on the three-electrode system, and the CNT-modified surface was treated with O2 plasma to pattern, clean, and activate the CNT layer. The optimized plasma treatment conditions were verified in terms of plasma power and treatment time by scanning electron microscopy (SEM), cyclic voltammetry (CV), and X-ray photoelectron spectroscopy (XPS).