A molecularly imprinted electrochemical enzymeless sensor based on functionalized gold nanoparticle decorated carbon nanotubes for methyl-parathion detection

Functionalized gold nanoparticles (FuAuNP) have potential applications because of their specific functional groups. p-Aminothiophenol (p-ATP) possesses double functional groups that can be used to form an S-Au bond and oligoaniline. Based on molecular imprinting technology and electrochemical technology, a novel enzymeless methyl-parathion (MP) sensor has been constructed with nanocomposites. The template molecule (MP) is embedded in the imprinting sites by p-ATP molecular self-assembly and FuAuNP electro-polymerization. The imprinting effective sites and the conductive performance are improved by gold nanoparticles decorated carbon nanotube nanocomposites (AuNP-MCNT). The linear relationships between peak current and MP concentration are obtained in the range from 0.1 to 1.1 ng mL(-1) and 1.1 to 11 ng mL(-1) , respectively. The detection limit can be achieved as low as 0.08 ng mL(-1) (3 sigma) with relative standard deviation of 3.8% (n = 5). This sensor was also applied for the detection of MP in apples and vegetables, with average recoveries between 95.2% and 105.7% (RSD < 5%). The results mentioned above show that the novel electrochemical sensor is an ideal device for the real-time determination of MP in real samples.