Aggregation-Induced Fabrication of Fluorescent Organic Nanorings: Selective Biosensing of Cysteine and Application to Molecular Logic Gate

• Published in: Langmuir Vol. 31; no. 18; pp. 5025 - 5032
• Main Authors: Mati, Soumya Sundar, Chall, Sayantani, Bhattacharya, Subhash Chandra
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 12.05.2015
• Subjects: Biosensing Techniques - methods; Cysteine - chemistry; Dynamic Light Scattering; Microscopy, Electron, Transmission; Nanoparticles - chemistry; Nanoparticles - ultrastructure; Naphthalimides - chemistry
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/acs.langmuir.5b00154

Self-aggregation behavior in aqueous medium of four naphthalimide derivatives has exhibited substitution-dependent, unusual, aggregation induced emission enhancement (AIEE) phenomena. Absorption, emission, and time-resolved study initially indicated the formation of J-type fluorescent organic nanoaggregates (FONs). Simultaneous applications of infrared spectroscopy, theoretical studies, and dynamic light scattering (DLS) measurements explored the underlying mechanism of such substitution-selective aggregation of a chloro-naphthalimide organic molecule. Furthermore, transmission electron microscopy (TEM) visually confirmed the formation of ring like FONs with average size of 7.5–9.5 nm. Additionally, naphthalimide FONs also exhibited selective and specific cysteine amino acid sensing property. The specific behavior of NPCl aggregation toward amino acids was also employed as a molecular logic gate in information technology (IT).