Quartz crystal microbalance determination of acephate based on a molecularly imprinted polymer and sulphur-doped copper ferrites.

Acephate (ACE), an effective systemic insecticide, plays a significant role in agricultural pest control. For many decades, this compound has been used to manage various insect infestations in crops, contributing to healthier yields. Hence, the detection of ACE serves as a critical indicator, signaling potential environmental degradation, public health risks, and economic challenges, thereby prompting necessary policy adjustments. The sulphur-doped copper ferrites (S@CuFe2O4) were initially synthesized through a hydrothermal treatment process. Subsequently, quartz crystal microbalance (QCM) chips incorporating S@CuFe2O4 were fabricated. This fabrication was accomplished by providing the inherent interaction between the gold surface of the QCM chip and the sulphur component present within the S@CuFe2O4 nanomaterial. A molecularly imprinted QCM sensor based on S@CuFe2O4 was developed by a UV polymerization technique. This sophisticated fabrication process involves the integration of methacryloylamidoglutamic acid (MAGA) as the monomer and N,N'-azobisisobutyronitrile (AIBN), which served as the crucial initiator. This innovative sensor exhibited a linear response range, spanning from 1.0 × 10-9 to 1.0 × 10-8 mol L-1. Furthermore, its sensitivity was remarkable, achieving a low limit of detection (LOD) at 3.30 × 10-10 mol L-1. The newly developed QCM sensor was effectively utilized for measurements in real apple juice samples, demonstrating high recovery rates. Additionally, an investigation was conducted to assess the sensor's selectivity, evaluate its repeatability and stability, and confirm its reproducibility.