Production of multi-walled carbon nanotube/poly(aminoamide) dendrimer hybrid and its application to piezoelectric immunosensing for metolcarb

This study described the synthesis and characterization of a multi-wall carbon nanotube/poly(amidoamine) dendrimer (MWCNT-PAMAM) hybrid material and its application in the fabrication of piezoelectric immunosensing platform. The aim of modifying PAMAM dendrimers onto the MWCNT surface was to improve its antibody adsorption and dispersion in aqueous phase, which was contributed to enhance the sensitivity and stability in piezoelectric immunoassay procedure. The adsorption performance and properties of the MWCNT-PAMAM hybrid were investigated using the Langmuir and Freundlich isotherm models, and possible mechanisms were discussed. The maximum antibody adsorption capacity was estimated as 147.06 μg μg−1, which is higher than any value currently reported for MWCNT. Based on these results, we developed a novel MWCNT-PAMAM-based piezoelectric immunosensing platform, which offered a stable, sensitive and accurate immunoassay for the determination of amounts of a carbamate pesticide-metolcarb, resulting in a linear range of 0.1–50.0 mg L−1 with detection limit of 0.019 mg L−1. And the mentioned immunosensing platform also exhibited satisfactory application capability in spiked apple and orange juice samples with recoveries of 81.9–101.2% and a standard deviation of 2.1-6.8% (n = 7).