[PÓSTER] New fluorescent Schiff base modified nanocellulose-based chemosensors for the selective detection of Fe3+, Zn2+ and Cu2+ in semi-aqueous media and application in seawater sample

Resumen

Cellulose is the most abundant linear carbohydrate bio-polymer in nature. It’s well-known as the most renewable, biocompatible, biodegradable, cost-effective and eco-friendly. In recent years, the shift from MCC to nanocellulose NC has rapidly attracted a great attention and has gained much interest as a new class of nanoscale biopolymers and as the new renewable source from both academia and industry researchers due to its promising potential in applications. NC is specifically characterized by a great dispersibility, high aspect ratio, large surface area, high mechanical strength, high crystallinity and thermal expansion coefficient. Thus, Schiff bases with an azomethine or imine (-C=N-) group have been extensively designed and used in field of cation species sensing, anions, proteins and organic substances, because of their simple preparation, high yield and easy structural modifications that can coordinate different analytes via the pair of electrons of azomethine nitrogen (-C=N) that make various complexes. Fluorometric chemosensors/probes are very effective for the detection and quantification of heavy metal ions, being the recognition simple process, that leads to high sensitivity, distinguished selectivity and excellent efficiency at low-cost. However, these small molecules are sometimes unstable in the surrounding changes in solutions. So, a new alternative has recently proposed using Schiff base-modified cellulose. For example, WANG et al. (2023) [1] developed a fluorescent coumarin derivative grafted dialdehyde cellulose-based probe for the detection of Fe³⁺. In this study, four new fluorescent dyes, namely, S₁: (PDA-DANC), S₂: (SAL-PDA-DANC), S₃: (BrSAL-PDA-DANC) and S₄: (ClSAL-PDA-DANC) have been successfully synthesized from (DANC) for the detection of heavy metal. The microstructural and photophysical properties of (NC), (DANC) and the synthesized dyes were investigated by FT-IR, SEM-EDX, XRD, TGA, DLS and photoluminescence.