Novel self-assembled fluorescent tripeptide nanoparticle for sensitive detection of sulfadiazine

Fluorescent tripeptide nanoparticles (PNPs) emitting cyan fluorescence were first synthesized using a Trp-Phe-Phe/Zn(II)-based self-assemble method. Molecular docking and dynamics simulations were employed to elucidated the self-assembly process of PNPs, the underlying driving forces, and their influence on the fluorescence properties of PNPs. The resultant PNPs were functionalized with an aptamer specific to sulfadiazine (SDZ), thereby creating a highly sensitive fluorescent probe. This probe demonstrated exceptional sensitivity and selectivity for SDZ detection, leveraging the inner filter effect to induce significant fluorescence quenching. The method demonstrated a wide linear range (0-200 ng/mL) and a low detection limit (0.4 ng/mL). Validation in spiked real samples (tap water, beef, chicken, and fish muscle) yielded recoveries of 83.20-114.08 % with relative standard deviations of <7 %, confirming its accuracy and reliability. This study provides insights into the assembly mechanism of tripeptide nanoparticles and offers a practical tool for food safety monitoring.