Development of a novel fluorescent probe for real-time quantification of serum albumin

Serum albumin (SA) is a highly water-soluble plasma protein essential for maintaining physiological homeostasis. It plays a crucial role in supporting liver and kidney function and regulating plasma osmolality. Reduced SA levels are frequently linked to liver failure and chronic hepatitis, emphasizing the urgent need for low-cost, accurate, and rapid methods for SA analysis. In this study, we have developed a fluorescent probe, triphenylamine derivative substituted with rhodanine-3-acetic acid (mRA),that exhibits a robust fluorescence response upon binding to bovine serum albumin (BSA). mRA is a bifunctional molecule containing both electron-rich and electron-deficient moieties, enabling strong intramolecular charge transfer (ICT)-mediated emission characteristics. mRA displays negligible fluorescence in aqueous solution. While it bind to BSA binding pocket, it restricts the intramolecular rotation, resulting in a significant increase in fluorescence intensity. A BSA concentration-dependent fluorescence enhancement was observed in the range of 0.01 to 300 μg/mL, with a detection limit as low as 8 ng/mL. This proof-of-concept was validated using BSA-spiked samples. Additionally, demonstrate that mRA can monitor BSA consumption/degradation in cell culture. The observed fluorescence recovery supports the effectiveness of this detection strategy as a viable alternative to conventional techniques. Moreover, this approach holds strong potential for the development of point-of-care diagnostic tools for detecting liver diseases.