A fluorescence switch sensor for detection of virginiamycin based on graphene oxide-supported carbon quantum dots and molecularly imprinted polymer
A fluorescence switch sensor was developed for the detection of virginiamycin, which was based on graphene oxide-supported carbon quantum dots (GO/C-dots) as the signal indicator and molecularly imprinted polymer (MIP) as the recognition template. First, GO/C-dots were prepared on the surface of an indium tin oxide (ITO) electrode. Then, MIP with virginiamycin as the template molecule and o-aminophenol as the functional monomer were synthesized on the surface of the GO/C-dots-modified ITO electrode. After removal of virginiamycin from the MIP, a sensor for specific adsorption of virginiamycin was obtained. The GO/C-dots generated a bright fluorescent signal, while virginiamycin quenched this fluorescence. Therefore, elution and adsorption of virginiamycin by the MIP acted as a switch to control fluorescence intensity. The obtained sensor has a high sensitivity and good selectivity, with a detection limit of 1.56 × 10−11 mol L−1 for virginiamycin.