A nanolevel sustainable fluorometric approach employing Eosin Y, a biological dye, as an innovative quenching-based biochemical sensor for linagliptin determination

• A green spectrofluorometric method for nano-level linagliptin determination. • Employment of Eosin Y dye as a sensitive, cost-effective biochemical sensor in aqueous medium. • High sensitivity was demonstrated, with LOD of 23 ng/mL and LOQ of 70 ng/mL. • The method was validated for crude material and pharmaceutical analyses. • Environmental sustainability was verified using different recent metrics. A new spectrofluorimetric method was devised to enable the accurate and eco-friendly determination of Linagliptin (LGT), a pharmaceutical agent recognized for its anti-diabetic properties. This investigation introduced a reliable, highly sensitive, and environmentally friendly analytical protocol for the examination and authentication of this therapeutic compound. The approach harnessed the swift electrostatic forces that arise between Eosin Y, an approved non-toxic biological stain, and LGT under mildly acidic conditions. This interaction resulted in a notable quenching of fluorescence for Eosin Y, predominantly observed at an emission wavelength of 557 nm. due to the formation of LGT-EY quenching bio-sensor. The method demonstrated exceptional analytical parameters, including limits of detection and quantification set at 23.3 ng mL -1 and 70.7 ng mL -1 , respectively, within a calibration range spanning 100.0–1400.0 ng mL -1 . Comprehensive optimization was performed to refine the factors influencing the interaction mechanism between the analyte and the dye. Detailed validation processes confirmed adherence to the International Council for Harmonization (ICH) guidelines, substantiating the procedure's precision and accuracy. The newly established method was successfully applied to measure LGT in its bulk form, formulated products, and various complex matrices. From a sustainability perspective, the procedure underwent a thorough evaluation using advanced tools aligned with green chemistry principles. Under the White Analytical Chemistry (WAC) framework, the assessment employing the RGB 12 model categorized the method as "white," indicative of its optimal environmental and operational efficiency. Further analysis using the new BAGI metric reinforced the method's sustainability and versatility by yielding high ratings in both dimensions, underscoring its reliability and extensive applicability.