Factorial design assisted electrochemical detection of cypermethrin using molecularly imprinted polyaniline

Abstract Cypermethrin (CYP), a widely used pyrethroid insecticide, poses significant risks to human health and aquatic ecosystems due to its extensive application. Despite the advantages of electrochemical sensors, such as simplicity, rapid response, and ease of use, the electrochemically inactive nature of CYP presents a major challenge for direct detection. In this study, a molecularly imprinted polyaniline (MIPANI)-based electrochemical sensor was developed for the sensitive detection of CYP using a label-based approach. A redox probe, potassium ferrocyanide/ferricyanide, was employed to generate signals based on the presence or absence of CYP at the sensor’s electroactive surface, enabling quantitative analysis from aqueous samples. Unlike previous studies relying on one-factor-at-a-time (OFAT) approaches, a two-level factorial design was applied to optimize key parameters. Statistical analysis (ANOVA, R 2 = 0.9956) confirmed the significant influence of these factors, ensuring a robust and reliable sensor performance. The total electrochemically active surface area analysis confirmed that MIP-eluted exhibited the highest active area, outperforming MIP-rebinded and non-imprinted polymer (NIP) forms. The sensor demonstrated a linear response from 0.01 to 0.5 μM, with a low detection limit (LOD) of 70 nM. Additionally, it exhibited good reproducibility and excellent selectivity against common interfering pesticides.