A Schiff base fluorescence switch-on probe derived from vitamin B6 cofactor for simultaneous detection of bovine serum albumin and ovalbumin

Abstract

The abnormal amount of albumin found in serum and urine samples is an important biomarker for a variety of illnesses. It is essential for clinical diagnosis, medicinal research, and preventative medicine to correctly assess the albumin concentration in actual biological samples. Herein, vitamin B6 cofactors derived Schiff bases obtained by condensing pyridoxal 5′-phosphate (PLP) with 2-aminophenol (L), pyridoxal with 2-aminophenol (L1) and PLP with aniline (L2) were employed for the detection of albumins. Schiff base L is non-fluorescent due to conformational flexibility and free intramolecular rotation, but becomes fluorescent upon protein–ligand complex formation with bovine serum albumin (BSA) and ovalbumin (OVA). Other Schiff bases L1 and L2 failed to response the presence of BSA and OVA. The intensity of fluorescence of L increases linearly with the increasing concentration of BSA and OVA, and the detection limits for BSA and OVA were estimated to be 0.18 µM and 0.13 µM, respectively. The molecular docking and molecular dynamics simulations were done to investigate the binding affinity and modes between the albumins (BSA and OVA) and L. The developed detection method was applied for the detection of BSA and OVA in real biological samples of milk, serum, egg white and urine, with satisfactory recovery.