Metal-organic framework integrated SPR sensor with enhanced sensitivity for selective chlorpyrifos detection in foods

In this study, the metal-organic framework modified chlorpyrifos imprinted (CPF-MOF@MIP), and non-imprinted (MOF@NIP) poly(2-hydroxyethyl methacrylate-N-methacryloyl-L-tryptophan methyl ester) based surface plasmon resonance (SPR) sensors was prepared for the real-time detection of chlorpyrifos from food samples. Surface characterizations of CPF-MOF@MIP and MOF@NIP SPR sensors were performed using Energy-Dispersive X-ray Analysis, atomic force microscopy, and contact angle measurements. Real-time kinetic analyses were performed over a concentration range of 0.05 to 100 ppm. The limit of detection (LOD) and the limit of quantification (LOQ) for CPF-MOF@MIP SPR sensor were calculated as 0.019 ppm and 0.064 ppm, respectively. In selectivity studies performed with CPF-MOF@MIP SPR sensors, it was determined that chlorpyrifos was detected 8.55 and 13.56 times more selectively than carbendazim and chlorothalonil, respectively. Additionally, the applicability of the prepared CPF-MOF@MIP SPR sensors was tested by detecting chlorpyrifos in cucumber and apple juices using both the prepared CPF-MOF@MIP SPR sensors and high-performance liquid chromatography.