There is a great interest in developing microelectronic devices based on nanostructured conducting polymers that can selectively electro-couple analytes at high sensitivity and low power. Nanostructured conducting polymers have emerged as promising candidates for this technology due to their excellent stability with low redox potential, high conductivity, and selectivity endowed by chemical functionalization. However, it remains challenging to develop cost-effective and large-scale assembly approaches for functionalized conducting polymers in the practical fabrication of electronic devices. Here, we reported a straightforward wafer-scale assembly of nanostructured hexafluoroisopropanol functionalized poly(3,4-ethylenedioxythiophene) (PEDOT-HFIP) on smooth substrates. This approach is template-free, solution-processed, and adaptable to conductive and nonconductive substrates. By this approach, the nanostructured PEDOT-HFIPs could be easily integrated onto interdigitated electrodes with intimate ohmic contact. At the optimized space-to-volume ratio, we demonstrated a low-power, sensitive, and selective nerve agent sensing technology using this platform by detecting sarin vapor with a limit of detection (LOD) of 10 ppb and signal strength of 400 times the water interference at the same concentration, offering significant advantages over existing similar technologies. We envision that its easy scale-up, micro size, small power consumption, and combination of high sensitivity and selectivity make it attractive for various wearable platforms.