Nanomolar level detection of metal ions by improving the monodispersity and stability of nitrogen-doped graphene quantum dots. (13th October 2021)

• Record Type: Journal Article
• Authors: Sohal, Neeraj; Bhatia, Simran Kaur; Basu, Soumen; Maity, Banibrata
• Is Part Of: New journal of chemistry. Volume 45:Number 42(2021)
• Page Start: 19941
• Page End: 19949
• Publication Date: 2021-10-13
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/d1nj04551b
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : Highly fluorescent and stable nitrogen-doped graphene quantum dots used as nanosensor for the selective and sensitive detection of Fe 3+ ions at nanomolar range based on the dynamic quenching. Abstract : Heteroatom doping of graphene quantum dots (GQDs) leads to the modification of their intrinsic properties, and is used as a fluorescent sensor for metal ions sensing. Here, nitrogen-doped GQDs (N-GQDs) were synthesized using graphene oxide as a precursor in the presence of N, N ′-dimethylformamide through a hydrothermal method. The particle size of N-GQDs was examined by a high-resolution transmission electron microscope (HRTEM) image. The surface functional groups and composition of N-GQDs were determined by X-ray photoelectron spectroscopy (XPS) and FTIR spectroscopic techniques. The introduction of nitrogen atoms in the framework of GQDs enhances its quantum yield, water solubility, and stability. The as-prepared nanoprobe has high sensitivity and selectivity for the label-free determination of Fe 3+ ions. The values of the quantum yield, average lifetime, different photophysical parameters (such as radiative ( k r ) and non-radiative ( k nr ) constants), rate of electron transfer ( k ET ), and electron transfer efficiency ( Φ EET ) have been evaluated to confirm the dynamic quenching between the N-GQDs and Fe 3+ ions. The prepared sensor showed high sensitivity with a very good limit of detection at the nanomolar range, i.e., 17 nM for Fe 3+ ions, as compared to the other sensors. The prepared sensing probe was also used for the sensing of Fe 3+ ions in iron supplementation, and it can be further used for different real sample detection. The synthesized fluorescent probe is very fast, inexpensive, and environmentally friendly.