Air pollution is evolving as a growing severe environmental concern, especially nitrogen oxide gases. Ultra-afforable and portable gas sensors with high-sensitivity and low-power consumption are of great significance for urban air-pollution monitoring. Herein, a functional PEDOT-ZnO nano-heterojunction gas sensor and monitoring system are demonstrated with low power consumption (~14.6 μW) and high sensitivity (0.02 ppm NO 2 ) based on accurate dielectrophoresis (ADEP) technology. These results show great potential in sustainable and low-power environmental monitoring. (Keywords: Accurate dielectrophoresis, Nano-heterojunction, Low-cost, and Low-power)