Micro-patterning of single-walled carbon nanotubes and its surface modification with gold nanoparticles for electrochemical paper-based non-enzymatic glucose sensor

Abstract

We developed a novel micro-patterning technique for single-walled carbon nanotubes (SWCNTs) on nitrocellulose (NC) membranes and characterized the mechanical and electrical properties of the patterned SWCNTs. The SWCNT patterns were successfully fabricated on wax-printed NC membrane by a vacuum filtration method within 15 min. The well-deposited SWCNT layer on the NC membrane exhibited strong adhesion and high conductivity due to the interconnection of the SWCNT layer in the porous structure of the NC membrane. The distinguishable patterns were resolved down to approximately 100 mu m. The patterned SWCNT had an average resistivity of less than 100 Omega/sq and showed excellent mechanical properties in repeated bending tests. The suitability of the patterned SWCNT electrodes for electronic devices was demonstrated successfully via a simple light emitting diode array. Moreover, for the application of the patterned SWCNT to electrochemical paper-based analytical devices (ePADs), the gold nanoparticles (AuNPs) were directly deposited on the SWCNT electrode for non-enzymatic glucose determination. The oxidation peak had a linear response with glucose concentration in the range between 0.5 and 10 mM. The ePADs exhibited a sensitivity of 240 mu A/mM.cm(2) and a detection limit of 148 mu M, which was derived from the electro-catalytic property of AuNPs toward glucose. Based on these results, we believe that the developed SWCNT patterning technique on paper substrates has great potential in ePADs.