A sensitive and robust electrochemical aptasensor for determining dopamine (DA) was developed using a grass carp skin collagen-graphene oxide (GCSC-GO) composite as a transducer and a label-free aptamer as a biological recognition element for the first time. In order to fabricate this sensor, the GCSC-GO composite was firstly prepared by ultra-sonication method and characterized by atomic force microscope, infrared spectroscopy, Raman spectroscopy, and electrochemical impedance spectroscopy. Subsequently, a label-free DA-binding aptamer was immobilized through strong interaction between collag...
