Considering that simple, fast, and cost-effective processing makes a difference in applicability, printing technologies are a favored solution as they minimize fabrication costs and personal training procedures. In the past decade, laser-processing has become popular for the fabrication of flexible miniaturized chemical and mechanical sensors . Commonly, porous laserpatterned carbon (LP-C) films with tailored properties are obtained by laser treatment of, for example, graphene oxide , polyimides , or lignins . In contrast to using polymeric precursors, naturally abundant, molecular compounds as starting materials provide strongly enhanced versatility to engineer materials by implementing specific functional groups. This study demonstrates that the proposed concept of single-step laser-patterning of optimized organic precursor coatings enables the fabrication of tailored sensor heterostructures even on flexible substrates. Here, we present a complete architecture for CO2 sensing on polyethylenetherephthalate (PET). The flexible nitrogen-doped LP-C (LP-NC) sensors exhibit high sensitivity to CO2 and a decent degree of selectivity even in humid environments in conjunction with good cycling stability and excellent mechanical properties. Adenine was used as the major precursor due to its rich nitrogen functionalities; glucose and sodium iodide were employed as foaming agent and porogen, respectively. The fabrication process was optimized in terms of precursor synthesis, primary coating composition/thickness, laser parameters, and reaction atmosphere to enhance the sensor response. The performance for CO2 sensing was proven in dry as well as humid environments. Structure formation and operating principle of the complex sensor were elucidated by comprehensive micro-and nanoanalyses.