 This study reports on the fabrication of lanthanum-doped zinc oxide, la-doped ZNO, films using sol-gel and spin-coating techniques, which exhibit high transparency, UV-blocking ability, and narrowed optical band gap. The ZNO, for 0.0 at .% la sensor showed the most significant gas response to carbon dioxide, CO2, gas with a value of 114.22% and a response time of 24.4 s and recovery time of 44 s, making it suitable for various industrial applications. The study also assessed the effect of humidity, selectivity, reusability, repeatability, detection limit, and limit of quantification. This article was authored by Khalid Abdelkaran, Rana Saad, Adele Mlsate, and others.