Sodium sulfite leads to the formation of fluorescent organic nanoparticles: Regulation from aqueous solution, cellular pathway to security design patterns

Abstract Fluorescent organic nanoparticles (FONs) play important roles in the monitoring and controls of biological systems. To fulfill such duties, we have to investigate how the nanoplatforms interact with living matters. Currently, very limited information concerning the potential risks and toxicity has been reported for FONs except the MTT assay. In this contribution, the amine-rich cationic precursor (polyethyleneimine) initiates one-pot copolymerization with methyldopa sesquihydrate and water-soluble fluorescent nanoparticles are afforded. The influence of reduction agent (sodium sulfite) on the luminescence, microstructure and crystallinity has been discussed and the corresponding stabilities are substantially improved. Further studies reveal that selective Cu2+ detection has been realized due to “on-off” change and the limit of detection is determined to be 52 nM. It has been discovered that glutathione (GSH) can recover its green luminescence in terms of strong affinity of GSH to copper ions. For the first time, three different cell viability experiments including MTS assay, Annexin V-APC/7-AAD kit and double stain technique have been performed to support the negligible cytotoxicity of FONs in living cells. Spectra imaging has been employed for the identification of Cu2+ and GSH in HeLa cells. In addition, the Cu2+-GSH pairs can generate an “AND” logic gate during recognition sequence operations. It will be the first example that the effectiveness of encryption and decryption has been verified via Cu2+ and GSH based on FONs.