Carbon dots synthesized by them‐trihydroxybenzene as the carbon source and its application on the detection of pH value

Abstract

New carbon dots (CDs) were prepared by a microwave method using m‐trihydroxybenzene and dilute sulphuric acid as raw materials. The as‐prepared CDs exhibited excellent water solubility and photoluminesence properties. The optimum excitation and emission wavelengths of the new CDs were at 365 nm and 465 nm, respectively. The fluorescence of the new CDs experienced remarkable changes in the presence of Britton–Robinson (BR) buffer solution with different pH values under 4°C after reacting for 70 min. In addition, a linear relationship between the logarithm of the relative fluorescence intensity ratio [lg(IF/IFo)] of CDs and the pH values of the sensing system ranging 1.81–5.72 was obtained, with a correlation coefficient of 0.9933. Thus, a sensitive and simple method to detect the pH value of solution was developed. Furthermore, the analytical application of detecting the concentration of acetic acid in vinegar was investigated. The detection values were found similar to the reference values, fully demonstrating a good linear relationship between the logarithm of the relative fluorescence intensity ratio of the CDs and the pH value of the system. Hence, the method could be used to detect the concentration of acetic acid in vinegar.

Dual-Emission Carbonized Polymer Dots for Ratiometric pH Sensing, pH-Dependent Generation of Singlet Oxygen, and Imaging-Guided Dynamics Monitoring of Photodynamic Therapy

“…The composition of the prepared CPDs is further characterized by the high-resolution X-ray photoelectron spectroscopy (HR-XPS) technique. The C 1s spectra (Figure c) show three binding energies of 283.6, 284.78, and 287.0 eV, representing CC/CN, C–O/C–N, and OC–O bonds, respectively . The N 1s spectra (Figure d) also display three peaks at 398.27, 399.5, and 400.55 eV, attributed to the CN bond, N–H bond, and C–N group, respectively .…”

A facile fluorescent sensor based on nitrogen-doped carbon dots derived from Listeria monocytogenes for highly selective and visual detection of iodide and pH

“…The procedure of pH detection was according to previous literature. 41 Specifically, 500 μL of Britton Robinson (BR) buffer at various pH values of 1.81, 1.98, 2.21, 2.87, 3.29, 3.78, 4.10, 4.78, 5.32, 5.72, 6.37, 6.80, 7.24, 7.96, 8.36, 8.69, 9.15, 9.62, 10.38, 10.88, 11.20 and 11.82 were prepared and then added 1.5 mL of the NCDs-LM dilute solution (100 μg mL −1 ), respectively. The obtained mixture was vortexed thoroughly to stand for 10 min at room temperature, and then transferred into the fluorescent cuvette for the FL measurement.…”

Hydrothermal synthesis of carbon dots and their application for detection of chlorogenic acid

“…Generally, the synthesis strategies for C‐dots can be divided into two approaches: the top‐down method and bottom‐up method [31] . Over the past few years, C‐dots have experienced rapid development in chemical sensing, and a series of functional C‐dots has been prepared for determination of metal ions and biomolecules [32–34] …”