Covalently Modified Graphene Oxide as Highly Fluorescent and Sustainable Carbonaceous Chemosensor for Selective Detection of Zirconium ion in Complete Aqueous Medium

Abstract

Zirconium, a medically important transition metal, found extensive application and was found to be relatively safe, however, continuous exposure will lead to adverse effects. Though zirconium is considered as a safe metal in biomaterials, no reliable sensing methodologies have been developed. In the present report, for the detection of medically influential zirconium(IV) ions, a graphene-based carbonaceous material has been developed. Covalent modification of graphene oxide (GO) with 2-bis(pyridine-2-ylmethyl)amino)ethan-1-ol (PAE) provides a new material GOP which is characterized using various analytical techniques such as elemental analysis, energy dispersive spectroscopy (EDS), FTIR, PXRD, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and microscopic techniques SEM and HRTEM. All the analytical characterization techniques strongly supported the formation of covalently 2-bis(pyridine-2-ylmethyl)amino)ethan-1-ol tethered GO through an ester bond. Upon testing with a series of metal cations, intriguingly, an excellent photoluminescence response has been selectively originated from GOP with Zr(IV) in aqueous medium and it is utilized for the detection of Zr(IV). High selectivity toward Zr(IV) over the presence of other common coexisting metal ions was also demonstrated. Specific "turn-on" fluorescence response of GOP in the presence of Zr(IV) ion is rationalized via Fluorescence Resonance Energy Transfer (FRET) mechanism owing to the presence of ester bond as a spacer which brings PAE and GO closer. Further, the GOP is highly stable and sustainable, could recover and reuse for further sensor studies. The newly developed carbonaceous GOP material offers a new methodology for the detection of Zr(IV) in an aqueous medium with LOD of 27 ng/mL.

Graphene oxide-derived carbonaceous sensor: turn-off fluorescence sensor for nanomolar detection of ruthenium ions in aqueous medium

“…Meantime, the same GOP probe is highly responsive towards Zr(IV) and explored as a turn-on fluorescence sensor. 79 A similar inert response was also observed with GOPN (Fig. S10, ESI †).…”

Robust charge carrier engineering via plasmonic effect and conjugated Π-framework on Au loaded ZnCr-LDH/RGO photocatalyst towards H2 and H2O2 production

“…This increase in d-spacing is due to the presence of oxygen bound functional groups and confirms the formation of GO by oxidation of graphite via the followed Hummer's method. 44,45 Further, in the well-defined XRD pattern of LDH, all the identifying peaks were observed at Bragg's angle 2θ = 11.5°, 23.43°, 34.3°, 38.8°, 47.3°, 59.6°, and 61.1°and are indexed to (003), (006), (012), (015), (018), (110), and (113) basal planes representing the rhombohedral phase (JCPDS no. 38-0486) and having R3m as the space group, respectively (Fig.…”

“…As shown in the FTIR spectrum of GO, the band at about 1722 cm respectively. 19,44,47 The absorption band located at 2360 cm −1 in GO, LDH/RGO, and Au@LDH/RGO samples was due to the presence of CO 2 /CO 3 2− in the samples. A broad spectrum was recorded over 3300-3600 cm −1 in the case of all the prepared samples that corresponds to the -OH stretching vibration of the carboxylic acid with phenolic groups of GO and surface hydroxyl groups with intercalated water molecules of LDH, respectively.…”

“…A broad spectrum was recorded over 3300-3600 cm −1 in the case of all the prepared samples that corresponds to the -OH stretching vibration of the carboxylic acid with phenolic groups of GO and surface hydroxyl groups with intercalated water molecules of LDH, respectively. 12,44,47 After the composite formation between LDH and GO, the broadness of the -OH stretching band slightly decreased, suggesting strong interaction between them. More importantly, LDH and LDH based nanohybrids, i.e., LDH/RGO and Au@LDH/RGO, showed weak bands at 1630 and 1396 cm −1 for the H-O-H bending vibration of water molecules.…”

Functionalized graphene oxide materials for the fluorometric sensing of various analytes: a mini review

“…Belinda Asha et al constructed a covalent-modified GO-based carbonaceous material as the highly fluorescent chemosensor 23 for the specific recognition of Zr 4+ ions in aqueous solution. 85 The sensor was prepared by functionalizing GO with 2-bis((pyridine-2-ylmethyl)amino)ethan-1-ol (PAE) and characterized by various analytical techniques. Covalent bond formation between GO and PAE through the ester linkage was supported by all the characterization techniques.…”