Highly Selective Dopamine Sensor based on an Imprinted SAM/Mediator Gold Electrode

A new concept of molecular imprinted polymer (MIP) electrode was proposed for amperometric detection of dopamine (DA). The MIP electrode was fabricated based on a screen-printed gold electrode. Thioglycolic acid (TGA) and allyl mercaptan (AM) were bounded on the gold electrode by covalent bonding to control the TGA density. The mediator, quercetin (Q), was also covalently bonded to the carboxyl group of TGA by using the carboxyl activation agent: 1-ethyl-3-(3-dimethylamino-propyl) carbodiimide (EDC). Molecularly imprinted poly(methyl methacrylate) (PMMA) was polymerized by UV curing. Different surface distribution densities of TGA were studied for realizing the recognition abilities of MIP electrodes. The TGA density was well controlled on the gold surface and the DA recognition ability was correlated to it.