Abstract
The concentration of sodium and potassium ions in biological fluids, such as blood, urine and sweat, is indicative of several basic body function conditions. Therefore, the development of simple methods able to detect these alkaline ions is of outmost importance. In this study, we explored the electrochemical and optical properties of graphene quantum dots (GQDs) combined with the selective chelating ability of the crown ethers 15-crown-5 and 18-crown-6, with the final aim to propose novel composites for the effective detection of these ions. The results obtained comparing the performances of the single GQDs and crown ethers with those of the GQDs-15-crown-5 and GQDs-18-crown-6 composites, have demonstrated the superior properties of these latter. Electrochemical investigation showed that the GQDs based composites can be exploited for the potentiometric detection of Na+ and K+ ions, but selectivity still remains a concern. The nanocomposites showed the characteristic fluorescence emissions of GQDs and crown ethers. The GQDs-18-crown-6 composite exhibited ratiometric fluorescence emission behavior with the variation of K+ concentration, demonstrating its promising properties for the development of a selective fluorescent method for potassium determination.
Highlights
Sensors for the selective quantification of sodium and potassium ions are of crucial importance in clinical diagnostics [1,2,3]
These ions are essential electrolytes for human homeostasis and changes in their concentrations can be related to serious complications for health, such as compromised heart function [4], cystic fibrosis [5], kidney failure [6], diabetic ketoacidosis [7] and adrenal disorders [8]
The coupling reaction between 2-aminomethyl-15-crown-5 (NH2 -15-crown-5) or 2aminomethyl-18-crown-6 (NH2 -18-crown-6) to the surface of graphene quantum dots (GQDs) was performed by activating the carboxylic functionalities present on the graphene surface using EDC/HOBt and 0.1 equivalent of DMAP, leading to the formation of amide bonds between these groups and the crown ethers (Scheme 1)
Summary
Sensors for the selective quantification of sodium and potassium ions are of crucial importance in clinical diagnostics [1,2,3]. Sodium is the most abundant cation present in extracellular fluids, with a concentration rate between 135 and 145 mEq/L, while potassium represents the most abundant cation inside cells, with concentrations in the range of 140–150 mEq/L [9]. The evaluation of the concentrations of these electrolytes, in serum, and in sweat and in dermis, can provide important information on the human body’s hydration status [11,12] Their quantification can provide important information for therapeutic interventions in elderly people, especially in clinical or nursing home settings, and for sports performance optimization. Their precise, sensitive and, if possible, contemporaneous monitoring, could allow the early diagnosis
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
