Abstract: Sulfur dioxide (SO₂) is a hazardous air pollutant with significant implications for the environment and human health.Traditional detection methods for SO₂ are challenged by limitations such as poor specificity and high operational costs.This study introduces an innovative approach for SO₂ detection using chemiresistive sensors composed of single-walled carbon nanotubes (SWCNTs) and 1, 8-bis(tetramethyl-guanidino)naphthalene with highly active protonized guanidino ionic groups through vdW interface heterostructure.This carbon nanotube composite sensing film serves as the core to construct a chemiresistive gas sensor, the developed sensors demonstrate a low detection limit of 12.8 ppb for SO₂ at room temperature along with high specificity to common gases such as NO₂ and CO₂, offering a costeffective, highly sensitive, and specific solution for SO₂ detection.