This paper presents a state-of-the-art planar microwave sensor designed for highly precise alcohol characterization in aqueous solutions, with a primary focus on its application in COVID-19 disinfectants. Modified from the Jerusalem patch, the sensor operates at 5.58 GHz, achieving a unique balance between heightened sensitivity and cost-effectiveness. A tailor-made 3D-printed case minimizes errors, securely housing the sensor and feeding tube. The sensor effectively discriminates between ethanol and methanol, revealing a notable 16 MHz frequency gap. In COVID-19 applications, it maintains alcohol percentages at 65-75%, with 1% increments. The paper outlines a mathematical model extracting concentrations with the maximum error of only smaller than 1.81%, affirming the sensor's precision. Beyond technical prowess, the sensor's non-destructive nature, real-time monitoring applicability, and freedom from life-cycle limitations mark it as an innovative tool for checking the percentage of alcohol and types of alcohol before using it to kill the virus, contributing significantly to global efforts on disinfectant measurements with noninvasive nature and high precision. This modified Jerusalem sensor stands as a transformative solution, offering unprecedented advantages in design, operational capacity, and broader support for virus-killing applications.