A molecularly imprinted electrochemical sensor based on multiwalled carbon nanotube-gold nanoparticle composites and chitosan for the detection of tyramine

A novel sensitive molecularly imprinted electrochemical sensor has been developed for selective detection of tyramine by combination of multiwalled carbon nanotube-gold nanoparticle (MWCNT-AuNP) composites and chitosan. MWCNT-AuNP composites were introduced for the enhancement of electronic transmission and sensitivity. Chitosan acts as a bridge for the imprinted layer and the MWCNT-AuNP composites. The molecularly imprinted polymer (MIP) was synthesized using tyramine as the template molecule, silicic acid tetracthyl ester and triethoxyphenylsilane as the functional monomers. The molecularly imprinted film displayed excellent selectivity towards tyramine. Under the optimum conditions, the current response had a linear relationship with the concentration of tyramine in the range of 1.08 × 10−7 to 1 × 10−5 mol/L, with a limit of detection 5.7 × 10−8 mol/L. The proposed sensor exhibited excellent repeatability, which was better than the result from previous literature. The relative standard deviation (RSD) of the repeated experiments for tyramine (5 mmol/L) was 7.0%. Determination of tyramine in real samples showed good recovery.