A chip-LSPR sensor based on magnetic molecularly imprinted polymer nanoparticles for in-situ determination of sulfadiazine

A simple chip-localized surface plasmon resonance (LSPR) sensor with a handmade sample pool is constructed based on the transmission mode of the UV–vis spectrophotometer to detect sulfadiazine (SDZ) by combining magnetic molecularly imprinted polymers nanoparticles (MMIPs NPs) as adsorbent and signal amplification reagent. The interaction between SDZ and methacrylic acid (MAA) was analyzed at molecule level (Gaussian 09 software), which indicates that the main interacting sites of SDZ and MAA are respectively O2, O3, H24 and H4, O2. The LSPR signal generated by SDZ-captured MMIPs NPs is 1.52 times compared with that of SDZ alone. The LSPR sensor shows a linear response for SDZ in concentration range from 1 to 100 ng/mL with a detection limit of 0.64 ng/mL. Meanwhile, the selectivity of LSPR sensor coupled with MMIPs NPs is better compared to magnetic non-molecularly imprinted nanoparticles(MNIPs NPs) for SDZ detection. Significantly, the chip-LSPR sensor shows strong anti-interference to actual sample matrix (recoveries range from 80.66 % to 122.21 %). This work provides an efficient strategy for building high-performance chip-LSPR sensor.