We investigated sensing properties on NOx (g) of single tellurium (Te) nanoribbon-based nanodevices. The synthesized Te nanoribbons were aligned at well-defined locations using a lithographically patterned nanowire electrodeposition (LPNE) technique. The shape and length were feasibly modified by the designed lithographical pattern, and the width was tailored by the applied electrochemical parameters. Temperature-dependent electrical resistance was analyzed with as-synthesized and annealed Te nanoribbons in the temperature ranging from 15 K to 300 K, where the calculated thermal activation energies of as-synthesized and annealed Te nanoribbons were 35.7 meV and 19.2 meV, respectively. Room-temperature sensor performance of as-synthesized and annealed single Te nanoribbons on detecting NOx (g) was investigated as a function of the tailored concentration of NOx (g). Compared to a sensitivity of 16±2.9% on detecting NOx (g) of 10 ppm in the as-synthesized single Te nanoribbon sensor aligned between Au/Cr electrodes, the sensitivity of 21±3.2% on detecting NOx (g) of 10 ppm at room temperature was demonstrated by single Te nanoribbon-based sensor annealed at 200oC for 1 hour in 5 % H2/N2 (g). The effects of annealing on sensing properties have demonstrated the improved sensitivity in the annealed Te nanoribbons..