Since penicillin was discovered in 1928, antibiotics have been widely used all over the world . Due to antibiotic abuse, multidrug-resistant (MDR) bacteria can evade antibiotics and thus have become a great threat to human health. Hence, production of new antibiotics is highly desirable . Pharmacologists usually focus on the structure-activity relationships of antibiotics to enhance their activity, with their optical properties ignored. In fact, investigating their photophysical properties is of great significance to understand their working mechanism . It is reported that fluorescent antibiotic and its derivatives have great potential to become a new research tool to fight antibiotic resistance.