Objectives: In this study, a new optical chemical sensor to assess molybdenum ion by incorporation of 1(2-benzothiazolylazo)-2-hydroxy-3-naphthoic acid (BTAHN), dibutylphthalate (DBP) and sodium tetraphenylborate (NaTPB) to the plasticized poly vinyl chloride (PVC) matrices were prepared.Methods: When DBP was added to the membrane, the ionophore's tendency to act as a chromoionophore was greatly increased. Great stability, reproducibility, extended life time, and respectable selectivity for Mo6+ ion assessment throughout a wide number of transition, lanthanides, and heavy metals were all advantages of the accomplished sensor.Results: At optimum compositions and investigational circumstances, the sensor response was linear cross range of 8.5 x 10-8 to 4.4 x 10-5 mol/L. Sensor detection and quantification limits realistic on the definition that the sample amount results in a signal equal to the blank signal plus three and ten times of its standard deviation were establish to be 2.5 x 10-8 and 8.3 x 10-8 mol/L. The sensor reaction time (characterized as the time it required for the absorbance value to reach 95 %) was 3.0-5.0 min.Conclusions: The achieved optical sensor was successfully applied to assess Mo6+ ion content in water, food, plant, and environmental samples.& COPY; 2023 Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).