Single-walled carbon nanotubes (SWNT) have the potential to be utilized in materials for a variety of sensors. When individually dispersed, semiconducting SWNT exhibit band-gap photoluminescence at near-infrared (nIR) wavelengths. The nIR region is critical in many biological detection schemes, as interference from cell autofluorescence and light absorption of whole blood and tissue is low at these wavelengths. In previous work we report the synthesis of oligonucleotide-SWNT materials for detection of a specific DNA sequence. The oligo-SWNT allow for label-free nanoscale detection through a modulation in the nIR fluorescence energy caused by hybridization of complementary oligo strands on the nanotube surface. We report here in further studies an evaluation of this nanoscale sensor with respect to its size, geometry and kinetic properties.