Electrochemical determination of cefotaxime based on a three-dimensional molecularly imprinted film sensor

• Gold networks@ionic liquid (GNWs@IL) is obtained using IL as capping agent.
• GNWs@IL plays a key role to form three-dimensional modified electrode.
• This is the first time to use MIP for the electrochemical detection of cefotaxime.
• The sensor offers a response for cefotaxime in range from 0.0039 μmol L−1 to 8.9 μmol L−1.
• The sensor performed very well on the detection of serum and urine samples.

A novel electrochemical sensor is presented for the determination of cefotaxime (CEF), which is constructed by molecularly imprinted polymer (MIP), gold networks@IL (IL, 1-butyl-3-methylimidazolium tetrafluoroborate, [BMIM][BF4]) (GNWs@IL), porous platinum nanoparticles (PPNPs) and carboxyl graphene (COOH-r-GO). The GNWs@IL is prepared by directly reducing HAuCl4 with sodium citrate in [BMIM][BF4] aqueous solution. The PPNPs are well embedded in GNWs@IL due to the adhesion of IL to form GNWs@IL-PPNPs suspension, which is coated on a COOH-r-GO modified glassy carbon electrode to construct a porous three-dimensional networks modified electrode. Then, MIP is prepared by cyclic voltammetry at the modified electrode, using CEF as template and o-phenylenediamine as monomer. The factors concerning this assay strategy are carefully investigated. Under the optimal conditions, the electrochemical sensor offers an excellent response for CEF, the linear response range is 3.9×10−9~8.9×10−6 mol L−1 and the detection limit is 1.0×10−10 mol L−1. The electrochemical sensor has been applied to the determination of CEF in real samples with satisfactory results.