Nitrogen-doped carbon dot threads as a “turn-off” fluorescent probe for permanganate ions and its hydrogel hybrid as a naked eye sensor for gold(III) ions

A brief review on the synthesis, characterisation and analytical applications of nitrogen doped carbon dots

“…As shown in Fig. 6a–e, many research articles have shown NCDs as a reliable fluorescent/colorimetric probe for heavy metal ions such as Fe 3+ , Cu 2+ , Hg 2+ , Pb 2+ , and Co 2+ and anions MnO 4 − , 19 Cl − , 91 CN − (ref. 92), etc.…”

“…18 Similarly, we synthesized highly emissive NCDs in thread like structures to act as a fluorescent probe for permanganate ions and a UV-vis naked eye probe for gold ions. 19 As it is well known that carbon dots are an upcoming comprehensive material, many critical reviews are available based on the synthesis and applications of carbon dots in multiple areas. However, this review puts emphasis on nitrogen doped carbon dots and their significance in analytical applications along with some discussion regarding synthesis, optical properties and characterization tools.…”

Versatile Red-Emissive Carbon Dots for Smart Textiles and Fluorescence Sensing

“…As new emerging luminescent nanomaterials, CDs have been widely used as fluorescent probes for metal ions, but CDderived fluorescent probes for MnO 4 − are scarce. 36−38 Most of the reported probes display fluorescence only in the blue and green wavelengths, 36,37 In this work, RCDs were facilely fabricated from ophenylenediamine and catechol in ethanol through a simple hydrothermal method (Scheme 1). The obtained RCDs showed excitation-independent red fluorescence emissions at 597, 647, and 707 nm, respectively.…”

A tough fluorescent nanocomposite hydrogel probe based on graphene quantum dots for the selective detection of Fe3+ ions

“…Recently, they have emerged as highly promising nanomaterials for fluorescence-based sensing applications due to their strong quantum confinement and edge effects, high fluorescence quantum yield, easily tunable photoluminescence, stable aqueous dispersion, low toxicity or even non-toxicity, good biocompatibility, tunable band gaps, and easy modification compared with traditional organic fluorescent materials and inorganic quantum dots. [13][14][15][16][17] Many reports indicated that GQDs had absolute selectivity and sensitivity toward some metal ions. Under the action of specific metal ions, GQDs can perform fluorescence quenching, so as to realize the detection of metal ions.…”

“…Hydrogels are a kind of soft-wet material composed of large amounts of water and three-dimensional cross-linked polymer networks that can encapsulate foreign molecules or nanoparticles within their spongy structure. 15,19 Recently, hydrogel materials have been widely used in the fields of continuous drug delivery, tissue engineering scaffolds, medical implants, nanocarriers, biosensing, soft actuators, and electronics. [20][21][22][23][24] However, due to their inherent structural heterogeneity and lack of an effective energy dissipation mechanism, most hydrogels have low mechanical strength, which greatly limits their applications.…”