The use of S₂O₈²⁻ and H₂O₂ as novel specific masking agents for highly selective “turn-on” fluorescent switching recognition of CN⁻ and I⁻ based on Hg²⁺–graphene quantum dots

Abstract

In this study, we report that both CN− and I− can enhance the fluorescent intensity of Hg2+–graphene quantum dots (Hg2+–GQDs).

A Fluorescence Switching Sensor for Sensitive and Selective Detections of Cyanide and Ferricyanide Using Mercuric Cation-Graphene Quantum Dots

“…The full width at half maximum (FWHM) was at 100 nm, which resembles that of most of the graphene quantum dots. 30 The fluorescence quantum yield of GQDs can also be determined by comparing the data with those obtained using quinine sulfate (quantum yield = 0.54 at 360 nm) as a reference. The quantum yield of the synthetic GQDs was calculated to be approximately 28.7%.…”

“…The turn-on sensor is superior to the turn-off sensor. It is more valuable and can find its applications in various fields. − …”

Nitrogen‐rich silicon quantum dots: facile synthesis and application as a fluorescent ‘on–off–on’ probe for sensitive detection of Hg2+ and cyanide ions

“…298 K, 303 K, and 313 K was investigated (Figure 11). The obtained results were then analyzed using the Stern-Volmer equation [32] : CdS/ZnS/As -0.25 μM [44] N-CQDs 0-20 μM 0.63 μM [45] SiNPs 0.001-0.4 μM 2.676 μM [46] IL@SiNPs 0-40 μM 0.45 μM [47] N,S-CDs 0.5-50 μM 8 3 n M [48] N-SiQDs 0.1-4 μM 2 4 n M [26] PDA NPs 0-10 μM 0.19 μM [49] N-CDs-RhB@COF 0.048-10 μM 15.9 nM [50] S-CDs 0.05-5.8 μM 33.3 nM Hg 2+ -GQDs Fluorescence 'turn-on' 0.5-8 μM 0.17 μM [57] CDs and AuNCs Ratiometric fluorescence 8 nM-12.5 μM and 12.5-75 μM 8 n M [58] CDs/AuNCs-PVA@CA Ratiometric fluorescence 0.2-20 μM 150 nM [59] DE-AuNC Ratiometric fluorescence 0.02-1 μM 1 0 n M [60] g-C3N4-Hg 2+ Fluorescence 'turn-on' -1.5 μM Hg 2+ ions (soft acids) showed a high affinity to nitrogen atoms (soft bases) on the surface of the NR-SiQDs. [41] Therefore, NR-SiQDs could conjugate with Hg 2+ to form NR-SiQDs/Hg 2+ complexes through coordination interactions.…”

Ultratrace Detection of Nickel(II) Ions in Water Samples Using Dimethylglyoxime-Doped GQDs as the Induced Metal Complex Nanoparticles by a Resonance Light Scattering Sensor

“…Because of their unique chemical, mechanical, and optical properties, graphene quantum dots (GQDs) have gained a lot of interest in the scientific community. − Compared to the standard semiconductor quantum dots (QDs), GQDs have many unique properties such as high biocompatibility, low toxicity, excellent solubility, robust photoluminescence (PL), and tunable band gaps, − which have prompted many possible applications of GQDs that include photodetectors, , bioimaging, − fluorescent agents, − adsorbent, , and sensors. , As a consequence, the identification limit, selectivity, sensitivity, and biocompatibility are very different in GQDs in comparison with that of QDs . Because of their excellent optical, electrical, mechanical, and thermal properties, GQDs have become one of the most common options to incorporate in sensors for detecting toxic metal ions .…”