Chromone based fluorescent organic nanoparticles for high-precision in-situ sensing of Cu2+ and CN- ions in 100% aqueous solutions

We present a systematic analysis of the formation mechanism of 3-formyl chromone based fluorescent organic nanoparticles (S3-FONs). S3-FONs express good water solubility and subsequent in-situ sensing of Cu2+ and CN- in aqueous and biological settings. Cu2+ displayed blue shift in absorption wavelength and efficiently quenches the emission intensity at 517 nm. Under the optimized conditions, the fluorescence intensity change established the feasibility for quantifiable analysis of ultra-trace concentrations of Cu2+ as inferred from an absolutely low limit of detection (12.3 nM) and the limit of quantification (40.59 nM). Standardized exercise revealed the in-situ formed S3- FONs-Cu2+ assembly acted as a secondary sensor for CN- via regeneration of fluorescence intensity with a limit of detection (21.4 nM) and limit of quantification (70.62 nM) and sketch the working principle of an IMPLICATION logic gate. The recovery analysis executed by spiking the known concentrations of Cu2+ and CN- in deionised water, tap water and river water samples, assured the robustness of the developed probe S3-FONs for in-situ sensing of ultra-trace levels of Cu2+ and CN- in real water sample matrix. These S3-FONs express promising applications in intracellular recognition of Cu2+ and CN- via cellular imaging in HeLa cells. (C) 2018 Elsevier B.V. All rights reserved.