Rapid mimetic micro-contact nano-fluorosensor based on molecularly imprinted polymers for the detection of amygdalin in biological matrices

Abstract

In this study, a mimetic fluorescence nanosensor based on a molecularly imprinted polymer was designed for the detection of amygdalin (AMG). Its characteristics and functional performance were investigated and recorded using ATR-FTIR, AFM and porosity tests. This designed sensor is considered superior to other reported techniques due to its low material consumption during both manufacturing and operation as well as its low cost and desirable performance characteristics, such as short response time, high stability and an appropriate detection limit. In situ surface imprinting was employed by incorporating methacrylic acid as the functional monomer, 2H-chromen-2-one as the fluorescence monomer, AMG as the template molecule, ethylene glycol dimethacrylate as the crosslinking agent, 2,2′-azobis(isobutyronitrile) as the initiator and a glass slide as the sensor medium. The detection mechanism relied on a reduction in the intensity of the fluorescence signal upon exposure to a solution containing AMG. The optimum monomer-to-crosslinking agent ratio was found to be 1 : 6, with a pH value of 4.5 being the most favorable. Mercury porosity test results showed that over 91% of the pores formed on the surface of the imprinted slides were in the range of 20–66 nm. Linearity analysis was performed by plotting a calibration curve for the nano-fluorosensor within the concentration range of 0.62–40 μg mL⁻¹, yielding a detection limit (LOD) of 0.19 μg mL⁻¹ and a limit of quantification (LOQ) of 0.62 μg mL⁻¹. The response time of the sensor was evaluated over the range of 5–150 seconds in buffer solution, urine and serum matrices, with 75 seconds as the optimal value. In general, the performance characteristics of the designed fluorosensor demonstrated its suitability for the selective detection of AMG in the biological matrices.