The textile industry's dyeing processes generate dyes that act as pollutants, contributing to the discoloration of wastewater and other environmental concerns. These nanosensors hold promise in detecting various azo-toxic dyes present in food products, thereby offering an expansive potential for future innovation in sensor design. Herein explores the advantages of nanosensors over traditional sensing methods, their diverse applications in utilizing nanomaterials, and the potential health consequences of azo dyes on human well-being. The article further outlines critical parameters for determining permissible limits and recommends an Acceptable Daily Intake (ADI) for azo toxic dyes. A groundbreaking innovation is a novel nanosensor employing cobalt nanoparticles for detection of Methylene Blue (MB) dye. Characterization of this nano cobalt sensor utilized various analytical tools, including Dynamic Light Scattering (DLS), Zeta potential analysis, Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), Fourier-Transform Infrared Spectroscopy (FT-IR), as well as BET surface area and pore size determination . Additionally, the sensor's mechanical stability was affirmed through investigation of the applied ionophore's lipophilicity using contact angle measurements, revealing an average contact angle of 121.59°. Notably, this attribute contributes to the robustness of the sensor. The sensor's responsiveness under differing pH and temperature conditions was carefully monitored. Impressively, the proposed sensor exhibited rapid and sensitive responses, even at very low dye concentrations (1 ppm), with a swift response time of 3 minutes.