Fast and efficient “on-off-on” fluorescent sensor from N-doped carbon dots for detection of mercury and iodine ions in environmental water

Ratiometric fluorescence detection of doxorubicin by R-CQDs based on the inner filter effect and fluorescence resonance energy transfer

“…5c), indicating a static quenching at 440 nm and a dynamic quenching at 550 nm. 31 The conditions for FRET generation require that the distance between the donor and acceptor is required to be 1–10 nm, in addition to the effective overlap of the absorption spectrum of the acceptor and the emission spectrum of the donor. For this purpose, the Förster distance between R-CQDs and DOX was calculated by the following equation: 32 “ k 2 ” denotes the relative orientation in space of the lepton dipoles of the donor and acceptor (in most cases, it is assumed to be 2/3), “ n ” is the refractive index of water (1.33), “ φ x ” is the fluorescence quantum yield of the donor R-CQDs alone (37.7%).…”

“…5c), indicating a static quenching at 440 nm and a dynamic quenching at 550 nm. 31 The conditions for FRET generation require that the distance between the donor and acceptor is required to be 1-10 nm, in addition to the effective overlap of the absorption spectrum of the acceptor and the emission spectrum of the donor. For this purpose, the Fo ¨rster distance between R-CQDs and DOX was calculated by the following equation: 32…”

Microfluidic preparation of optical sensors for biomedical applications

“…The sensor worked in an “on‐off” manner to detect Hg 2+ due to electron transfer between Hg 2+ and CDs, and in an “off‐on” manner to detect I − due to preferential binding between Hg 2+ and I − (Figure 3B). 39 In addition, fluorescent silicon NPs, graphene quantum dots, and other materials have also been studied as fluorescent sensors, 40 which are not elaborated here.…”

Green and facile synthesis of silicon-doped carbon dots and their use in detection of Hg2+ and visualization of latent fingerprints

“…The N-CDs were used as a fluorescent sensor based on an “on–off–on” mechanism, and could monitor Hg 2+ and I − with limits of 3.3 nM and 8.5 nM, respectively. 26 The tunable emission of the CDs endows them unique potential advantages in terms of optical properties. 27 Easy superficial modification provides the CDs with abundant surface functional groups, which result in good photostability, excellent solubility, and superior selectivity and sensitivity in detection applications.…”