Atmospheric pressure plasma functionalization of carbon nanotube dot-array with two-stage plasma treatments for the development of bio-chip sensors

An atmospheric pressure plasma jet (APPJ) technique was developed to functionalize amino groups to obtain plasma-functionalized carbon nanotube (CNT) dot-array as a precursor of biomolecules of the bio-chip sensor. To realize bio-chip sensors based on CNT, it is needed the proper control of their surface functionalization. An APPJ technique for CNT functionalization was implemented in the two-stages: (1) pre-treatment with by Ar gas -500 V dc bias and (2) post-treatment by Ar and NH3 gas mixture without substrate bias. Two-stages plasma treatment are important factors for performing surface functionalization in the APPJ, without any pre-treatment or when we only applying the post-treatment, no functionalization occur in the CNT dot-array.