Novel luminescent paper based calix[4]arene chelation enhanced fluorescence- photoinduced electron transfer probe for Mn2+, Cr3+ and F-

A novel structurally simple calix[4]arene attached 1-aminoanthraquinone associated lower rim calix[4]arene conjugate was synthesized and has been used as turn on/off/on fluorescence probe for Mn2+, Cr3+ and F-. This chelation enhanced fluorescence - photoinduced electron transfer (CHEF-PET) based TAAC probe has been applied for its analytical application in real samples such as Mn2+ from blood serum, Cr3+ and F- from industrial effluent with 94-99% recovery. The limit of detection of this sensor is found to be 11 nM for Mn2+, 4 nM for Cr3+ and 19 nM for F- with the concentration range of 0-120 nM. Further, we report an easy-to-use, low cost and disposable paper-based sensing device for rapid chemical screening of Mn2+, Cr3+ and F-. The device comprises fluorescent sensing probes embedded into a nitrocellulose matrix where the resonance energy transfer phenomenon seems to be the sensing mechanism. It opens up new opportunities for simple and fast screening in remote settings where sophisticated instrumentation is not always available. The MOPAC-2016 software package has been used to optimize the TAAC using PM7 well established method and calculates the HOMO-LUMO energy band gap for structure TAAC and TAAC with Mn2+, Cr3+ and F- ion based structures.