Carbon‐dot‐based ratiometric fluorescent probe of intracellular zinc ion and persulfate ion with low dark toxicity

Abstract

Metal ions and anions play significant roles in biological systems and industrial processes, therefore it is important to develop good fluorescent probes to detect metal ions and anions. Here, N,O‐co‐doped carbon quantum dots (CDs) that could detect Zn2+ via a ratiometric fluorescence method were fabricated. The reaction between the as‐prepared CDs and zinc acetate gave the composite CDs–Zn, in which fluorescence changed ratiometrically upon addition of S2O82−. With change in excitation light, the emission peaks of the CDs and CDs–Zn were kept fixed while intensity changed. CDs and CDs–Zn exhibited good photostability, thermal stability, selectivity, and strong anti‐interference ability. In addition, CDs and CDs–Zn displayed low dark toxicity under physiological temperatures. Ratiometric fluorescence imaging of intracellular Zn2+ and S2O82− was carried out in living HeLa cells for both of these probes. Compared with reported ratiometric fluorescent hybrid nanosensors based on organic dyes and inorganic nanomaterials, the as‐prepared CDs and CDs–Zn had low toxicity, and were easy to synthesize.

Simple and eco‐friendly synthesis of crude orange‐peel‐derived carbon nanoparticles for detection of Fe3+ and ascorbic acid

“…Fluorescence switch is one of the commonly used methods for detecting various analytes by CDs, but the switch principle varies according to different properties of different CDs and analytes. [ 30–33 ] Most of the current methods for detecting AA based on CDs use the ‘on–off–on’ mechanism in which fluorescence of CDs is first quenched by Fe 3+ then recovered from reduction of Fe 3+ to Fe 2+ in the presence of AA. [ 34–37 ] In this study, the order of reaction was adjusted to ensure a more complete reduction reaction between AA and Fe 3+ .…”

Carbon Dots for Intracellular Sensing

“…Several strategies have been adopted to develop CD-based methods for probing zinc ion (Zn 2þ ) in cells. [234][235][236][237][238] Zhang et al prepared a CD-based Zn 2þ sensor by modifying the surface of CDs with a specific Zn 2þ recognition group (a quinoline derivative) (Figure 10A). [234] The CDs were synthesized by the lowtemperature pyrolysis of CA and branched PEI.…”

“…Further, Bu et al synthesized unmodified N,O-codoped CDs which could directly interact with Zn 2þ , forming the CDs-Zn complex and quenching the fluorescence of the bare CDs (Figure 10D). [237] The CDs were prepared by hydrothermal treatment of 2-hydroxyisophthalaldehyde and o-phenylenediamine. After the addition of Zn 2þ to form the CDs-Zn complex, the fluorescence emission intensity at 430 nm was notably increased and the emission intensity at Figure 10.…”

Effect of various aqueous extracting agents on fluorescence properties of waste tea residue derived carbon dots (WTR‐CDs): Comparative spectroscopic analysis

“…[4] Therefore, CDs have been extensively applied in the areas such as biosensors and bioimaging, [5][6][7][8][9] photocatalysis, [10] optoelectronic devices, [11] and sensing/detection applications. [12][13][14][15][16] After the inception of CDs, several methodologies have been in use for their synthesis. The synthetic methods such as acidic oxidation, [17] ultrasonic, [18] electrochemical oxidation, [19] hydrothermal, [20] laser ablation, [21] microwave, [22] and arc discharge [1] were discovered to synthesize CDs.…”