Colorimetric sensor based on release control from liposomes by the formation of 2,2-bipyridine-Fe2+ complex

Abstract

In colorimetric detection, an analyte may be determined both qualitatively and quantitatively by keeping track of color changes that seem to be perceptible to the unaided eye. The uniform liposomes with diameters of 100 nm were synthesized from sphingomyelin and cholesterol. We comprehensively assessed 2,2-bipyridine's capacity to release from liposomes as well as the color shift to dark red caused by the formation of complexes between Fe2+ and 2,2-bipyridine for colorimetric detection. In addition, we extensively evaluated and examined factors influencing liposomal membrane leakage, such as pH value change, bulkiness of the molecular structure (2,2-bipyridine and doxorubicin), and the membrane rupture mechanism of triton X100. To provide the best circumstances for the color sensor from these liposomes, pH conditions and concentrations of triton X100 and Fe2+ were optimized. In addition, it has been confirmed and thoroughly described how pH breaks the liposome membrane and how Fe2+-Bipy changes color. The capacity to release from liposomes throughout time was studied via analysis of kinetic release models, including Fick's law, the Higuchi model, and the Korsmeyer-Peppas model. Our approach develops a method to is straightforward, quick to detect, and easily applied. This research holds promise as color color-sensing method for detecting viruses and pathogens in the future.