AIE-Active Turn-On' Sensors for Highly Selective Detection of Bovine Serum Albumin

Tetraphenylethylene (TPE)-based, two molecular 'Turn-On' probes i. e. 4,4',4'',4'''-(ethene-1,1,2,2-tetrayl)tetraphenol (tetrahydroxy-TPE, coded as: TPE-1) 4,4',4'',4'''-(ethene-1,1,2,2-tetrayl)tetraaniline and tetraamino-TPE, coded as: TPE-2) have been successfully reported for the selective detection of bovine serum albumin (BSA) over its other biological competitors. The BSA sensing has been investigated using UV-Vis absorption and fluorescence emission spectroscopy, where the fluorescence of probes tetrahydroxy-TPE and tetra-amino-TPE was significantly enhanced in the presence of BSA. The BSA sensing was also characterized by visual eye detection, where a significant color change of probe tetrahydroxy-TPE and tetra-amino-TPE was observed with BSA. The detection limit for BSA was calculated to be 0.2 nM and 1.41 nM for using probes tetrahydroxy-TPE and tetra-amino-TPE, respectively. The binding constant was observed to be1.8x103 M and 1.4x103 M for probes tetrahydroxy-TPE and tetra-amino-TPE, respectively. A molecular docking study is also performed to investigate the detailed interactions between probes tetrahydroxy-TPE and tetra-aminoTPE with BSA. The lowest binding energy conformation for probes tetrahydroxy-TPE and tetra-amino-TPE was found at 8.1 kcal/mol and 8.2 kcal/mol, respectively.