Crown ether functionalized graphene oxide as ultrasensitive electrochemical sensor for detection of potassium ions

Metal ion sensing with graphene quantum dots: detection of harmful contaminants and biorelevant species

“…10 This selectivity was hypothesised to arise as a function of modulating sizes of crown ether-like structures, within the graphene plane of the material, in much the same way as previously reported PN-GQDs, whereby cation selectivity was determined by ion size and charge density. 10,131–133 LODs were the lowest reported thus far for GQD detection of these ions (Ca 2+ = 2 pM, Mg 2+ = 20 pM, Sr 2+ = 8 pM, Ba 2+ = 2 pM), with a higher static quenching efficiency observed than for PN-GQDs. 10,131 One possible drawback of this method is the aforementioned heterogeneity of materials produced using bottom-up synthetic methods, as is the case in this example.…”

“…10 This selectivity was hypothesised to arise as a function of modulating sizes of crown etherlike structures, within the graphene plane of the material, in much the same way as previously reported PN-GQDs, whereby cation selectivity was determined by ion size and charge density. 10,[131][132][133] LODs were the lowest reported thus far for Fig. 10 The introduction of crown ether-like structures into the carbon framework of GQDs from alizarin precursors for the subsequent detection of biologically relevant metal ions.…”

High strontium adsorption performance of layered zirconium phosphate intercalated with a crown ether

“…The crown ether is composed of multiple ethoxy (C–C–O) units, and the multiple powered oxygen atoms in the structure allow it to form host–guest complexes with alkali and alkaline earth metal ions. 32,33 As the diameter of Sr 2+ (0.23 nm) is close to the size of the cavity in 18-crown-ether-6 (18C6) and its derivatives, which is in the range of 0.26–0.32 nm, Sr 2+ can enter the cavity to interact with O atoms in 18C6 to form stable complexes. 19,34 As a result, the 18C6 has become the most studied extractant in the removal of Sr-90 from highly radioactive waste streams.…”

Electrochemical and Fluorescent Properties of Crown Ether Functionalized Graphene Quantum Dots for Potassium and Sodium Ions Detection

“…Their cation selectivity is dependent on the size and charge density of the ion and the crown ether cavity and is mainly achieved by ion-dipole interactions [21]. Among them, 15-crown-5 and 18-crown-6 are good hosts for sodium and potassium ions, respectively, and have been investigated for the development of selective fluorescent, potentiometric and electrochemical sensors for the detection of these biologically important electrolytes in solution [22][23][24][25][26].…”

“…A graphene-based fluorescence resonance energy transfer (FRET) sensor linked to an ion-selective crown ether revealed a detection limit of K + ion of about 1 × 10 −5 M [23]. Reduced graphene oxide (rGO) covalently conjugated with 18-crown-6 ether displayed the ability to detect K + ions down to the micromolar range [25], while an electrochemical sensor based on 1-aza-18-crown-6 functionalized GO reported a detection limit for K + ion of 10 −15 M [26]. The next generation of the graphene family, the zero dimensional graphene quantum dots (GQDs), received significant interest within academia and industry over the last few years due to their remarkable physicochemical properties [31,32].…”