Nitrogen-Doped Graphene Oxide Dots-Based “Turn-OFF” H₂O₂, Au(III), and “Turn-OFF–ON” Hg(II) Sensors as Logic Gates and Molecular Keypad Locks

Abstract

Fluorescent nitrogen-doped graphene oxide dots (NGODs) have been demonstrated as an on–off nanosensor for the detection of Hg 2+ , Au 3+ , and H 2 O 2 . As compared to l -cystine, where the luminescence signal recovery results from the detachment of Hg 2+ from the NGODs, signal recovery through l -ascorbic acid (turn-off–on model) has been attributed to the reduction of Hg 2+ to Hg 0 . The sustainable recovery of the photoluminescence signal is demonstrated using common citrus fruits containing vitamin C ( l -AA), suggesting a promising practical usage of this sensing system. Additionally, the sensitivity of NGOD- and AA-originated signal recovery from the Hg(II)–NGODs mixture has been successfully tested in Hg 2+ ion-spiked tap water from three different places. Mimic devices were executed and verified on the basis of characteristic spectral changes, and the possible utility of this system in electronic security and memory element devices has also been demonstrated. Considering an easy synthesis process and excellent performance of NGODs, this investigation opens up new opportunities for preparing high-quality fluorescent NGODs to meet the requirements of many applications.

Persea americanaseed extract mediated gold nanoparticles for mercury(ii)/iron(iii) sensing, 4-nitrophenol reduction, and organic dye degradation

“…The unique opto-electro-chemical properties of MNPs, different ways for its application in sensing and remediation eld have been demonstrated. [7][8][9][10][11][12][13][14][15][16][17] It is worth mentioning that most of the researchers have reported the detection of heavy metal ions based on colorimetric approach due to simplicity and cost effectiveness where the outcome can be observed by the naked eye. 9,10 Although they are widely used, we still need to study an eco-friendly approach for sensing of heavy metal ions.…”

Recent advances in fluorescence probes based on carbon dots for sensing and speciation of heavy metals

“…With their carbon core and their easily tailored biocompatible functional groups on the surface, most of the CDs exhibit low toxicity, endowing them with great potential applications as fluorescent probes for HMs imaging in cells, bacterium, plants, and animals. In recent decades, there have been significant advances on CDs as fluorescence sensors for HM ions and their species and novel applications in environmental and food safety testing [21], cell and animal imaging [22,23], chemical logic gates [24], anticounterfeiting ink [25,26], fingerprint security, and document counterspy [27]. This review summarizes the recent advances on CDs, including CNs, CQDs, C-dots, carbon nitride dots (CNDs), GQDs, and PDs as fluorescence sensing platforms for HMs.…”

Preparation and Biomedical Applications of Multicolor Carbon Dots: Recent Advances and Future Challenges

“…In addition, the probable usefulness of this method in electronic security and memory element devices has also been exhibited. [ 161 ] Furthermore, Wu et al used tetraphenylporphyrin or its transition metal (Pd or Pt) complex as precursor to prepare the CQDs, Pd‐CQDs, and Pt‐CQDs, which was well demonstrated as fluorescent probes for the specific and sensitive detection of Fe 3+ ions in aqueous solution. [ 162 ]…”