We recently reported a sugar-induced bacterial release of 13-Docosenamide and its ability to quench fluorescein. This simple handle to monitor bacterial growth is readily applicable to develop a quicker antibiotic sensitivity testing method along with a low-cost field-use optical instrumentation. Conditions were standardized to perform this new procedure in the most preferred and CLSI-recommended microdilution format in 12-well strips. A simple and portable optoelectronic prototype was used to capture the image and read the fluorescence signal of the culture medium of the 12-well strips. This new Fluorescence Quenching Method along with the device enabled the choice of the right antibiotic within 8 h of sample collection from the patient. It was compliant to the Clinical Laboratory Standard Institute's quality control guidelines. Clinical assessment of the method using 440 urine samples from Urinary Tract Infection patients against 21 routinely used antibiotics showed a 94.3% match with the results of the Standard Disk Diffusion method. This new method saves the precious time taken for and the cost of antibiotic susceptibility testing for quicker and effective treatment with better compliance.