Investigation the influence factors on the selectivity and response time of the glyoxal-selective probe

Abstract

In this work, four o-phenylenediamine conjugated fluorescent probes 1-4 with different substituents on the amino group have been designed and prepared for investigation the influence factors including selectivity and response time of the probe toward glyoxal (GO). The introduced substitution groups include n-propyl, iso-propyl, tert-butyl and -phenyl 1-4 displayed sufficient selectivity toward GO. Due to the fact that GO normally existed in a hydration state in aqueous media, the reaction rates between 1-4 with GO extremely disobeyed the steric hindrance effect in most organic reactions. Compounds 3 and 4 with bulky substituted group presented faster reaction rates with GO than those of compounds 1-2. To further elucidate the properties of these compound, we selected compound 3 with best selectivity and fast response time as present compound for investigation the detailed recognition behaviors both in aqueous solution and in living cells. The probe 3 exhibited high selectivity and high sensitivity toward GO with a large Stokes shift (>100 nm), making it highly suitable for in vivo imaging research.