A 1,8-naphthalimide based chemosensor for intracellular and biofluid detection of Pd ions: microscopic and anticounterfeiting studies

• Published in: Analytical methods 2023-10, Vol.15 (38), p.51-517
• Main Authors: Kumar, Sanjeev, Sharma, Neha, Marok, Satwinder Singh, Kaur, Satwinderjeet, Singh, Prabhpreet
• Format: Article
• Language: English
• ISSN: 1759-9660; 1759-9679
• DOI: 10.1039/d3ay00948c

A naphthalimide based chemosensor ( NPG ), containing 1,8-naphthalimide as a fluorophore unit and pentaethylene glycol as a binding unit, has been used for the detection of Pd 2+ ions in 50% HEPES buffer-DMSO (pH 7.2) solution. The NPG showed aggregation induced emission enhancement (AIEE) properties in H 2 O-DMSO binary mixtures (0-90%) and the CIE plot of NPG in DMSO has x = 0.152, y = 0.102 coordinates corresponding to blue colour emission with 86% colour purity. Upon addition of Pd 2+ ions, NPG showed a decrease in fluorescence intensity associated with a colour change from fluorescent blue to non-fluorescent colourless solution. The lowest limit of detection for Pd 2+ ions was 75 nM. The mechanism of interaction of NPG with Pd 2+ ions leads to complexation induced aggregation caused quenching (ACQ) supported by DLS, SEM and AFM studies. The NPG has been successfully utilized for (i) intracellular detection of Pd 2+ ions (250 μM) in live MG-63 cells; (ii) detection of Pd 2+ ions in pharmaceutical (99.74 ± 0.6%), urine (98.20 ± 2.96%) and blood serum (99.17 ± 1.84%) samples and (iii) detection of Pd 2+ ions using silica coated TLC strips via a contact mode method. NPG can be used as a security ink for writing letters and alphabets for anticounterfeiting applications. We integrated penta ethylene glycol with 1,8-naphthalimide for (i) nanomolar detection of Pd 2+ ions in water, biofluids and live cells supported by morphological studies and (ii) anticounterfeiting labels.