Decoration of graphene with 2-aminoethanethiol functionalized gold nanoparticles for molecular imprinted sensing of erythrosine

In this account, sodium citrate was used as reductant and stabilizer to decorate reduced graphene oxide (rGO) with 2-aminoethanethiol (2-AET) functionalized and well-distributed gold nanoparticles (AuNPs), as well as to improve the sensitivity and stability of rGO deposited on the electrode surface. The molecular imprinted polymer (MIP) was prepared on the electrode surface using erythrosine (ERT) as the template molecule, and both m-dihydroxybenzene (m-DB) and o-phenylenediamine (o-PD) as functional monomers. A sensitive sensor was then fabricated for the direct determination of ERT. The prepared nanomaterials were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectrum analysis (EDX), and infrared spectroscopy (FT-IR). The properties of the resulting sensor were examined by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). The data revealed that the as-prepared sensor could achieve wide linear range (3.75 × 10 −8 to 1.50 × 10 −4  M) and low detection limit (4.77 × 10 −9  M), meeting the requirements of ERT trace analysis. The stability and reproducibility of the prepared molecular imprinted electrodes showed excellent long-term stability and relevant reproducibility, making these platforms promising for future electrochemical sensors.