Table 1 Details of various reported carbon dots (CD) used to develop latent fingerprints
From: A comprehensive review on the detection of latent fingermarks using carbon dots
S. no. | Composition | Preparation method | Characterization techniques | Size (nm) and shape | Application method | Surfaces | Luminescence characteristics | Advantages | Reference |
|---|---|---|---|---|---|---|---|---|---|
|  | P-doped carbon dots (CD-5) | NR | DLS, FTIR, HRTEM, NMR, PL, RS, X-ray-EDS, XPS, XRD, zeta pot. | 220–230, spherical | Powder dusting | Euro banknote, magnetic band, smartphone screen, and metallic surface of credit card | Orange fluorescence at 495 nm | Non-toxic, fast, and cost-effective synthesis | Algarra et al. (2019) |
|  | Cationic carbon dots (CD-17) | Microwave | FTIR, PL, RS, TEM, UV-Vis, XPS, XRD, ZP | 2–10 | Spraying | Glass, paper, aluminum foil, optical mouse, metallic alloy, porcelain | NR | Biocompatible, tunable fluorescence, safe to use, and 3rd-level details are visible in developed fingerprints | Bahadur et al. (2019) |
|  | CDs–Osi (CD-35) | Solvothermal | UV, PL, HR-TEM, FE-SEM | 2.36 nm Spherical | Powder method | Glass, aluminum foil, soft plastic bags, and hard plastic sheets | UV irradiation 365-nm wavelength | NR | Cao et al. (2024) |
| Â | Red carbon dots (CD-11) | Hydrothermal | FTIR, PL, TEM, UV-Vis, XPS | 2.4 | Spraying | Glass, aluminum foil, leather, plastic | Emit bright-red fluorescence under UV light | Fast, user-friendly, and portable, method for fingerprint detection | Chen et al. (2017) |
| Â | N-doped carbon dots (CD-10) | Microwave | AFM, FTIR, HRTEM, PL, UV-Vis, XPS, XRD | 8.1 (b-CD) 2.69 (o-CD), spherical | NR | Glue film | NR | Ease of use, non-toxicity, good dispersibility | Deng et al. (2019) |
|  | C-dot/p (DMA) (CD-19) | Hydrothermal | DLS, FTIR, NMR, PL, RS, TGA, UV-Vis, XPS | 8.7 ± 0.5, spherical | Dipping | Aluminum foil | Fluorescence signal when excited at 350 nm | Non-toxic, luminescent, significant visual contrast | Dilag et al. (2015) |
| Â | Blue carbon dots (CD-22) | Hydrothermal | FTIR, PL, TEM, UV-Vis, XPS, XRD | 3.2 | Powder dusting | Litmus paper, resin tabletop, glass, orange plastic ruler | Blue fluorescence under 365-nm UV light | NR | Feng et al. (2019) |
|  | Silica-based carbon dots (CD-2) | Pyrolysis | FM, PL, TEM | 19 ± 2, spherical | Powder dusting | Glass slide, bottle foil | Blue, red, or green when they are excited in the violet, blue, and green wavelength regions | Non-toxic, color tuneability, highly fluorescent hybrid nanopowder | Fernandes et al. (2015) |
|  | CdTe quantum dots (CD-16) | NR | UV, PL, FL, IR | 20–50, spherical | Transfer | Glass slide, black ceramic tile, painted polymer material, transparent plastic sheet | Emit fluorescence under 360-nm UV light | Finger ridge Details without background staining, resulting in good contrast For enhanced detection | Gao et al. (2011) |
| Â | White carbon dots (CD-9) | Carbonization | HR-TEM, FTIR, NMR, PL, RS, UV-Vis, XPS, XRD | 4, spherical | Dipping | Glass | Emit bright white fluorescence under 365-nm UV light | Suppress the ACQ effect | Jiang et al. (2018) |
|  | CdS/PAMAM carbon dots (CD-24) | Pyrolysis | FTIR, PL, TEM, UV-Vis, XRD | 10–40, spherical | Powder dusting | Glass, aluminum and copper foils, white ceramic, black marble, coin, iron and zinc sheets, plastic card, adhesive tape | Blue fluorescence under 365-nm UV light | Tunable photoluminescent performance | Jin et al. (2008) |
| Â | Zn/N-CDs@hydrotalcite (CD-32) | Hydrothermal method | XRD, SEM, TEM, FTIR, RS XPS, FS | NR | Powder dusting | Clear glass slide, aluminum foil, tiles, plastic Packing of beer bottle, paper, and leather | Fluorescence under 365-nm UV | NR | Li et al. (2023) |
| Â | Silica-based carbon dots (CD-8) | Hydrothermal | DLS, FTIR, PL, TEM, XPS, XRD | 102.4, monodisperse quasi spherical | Powder dusting | Aluminum foil, marble, transparent tape, wood, ceramic tile, black plastic, stainless steel | Blue fluorescence under 365-nm UV light | Tunable photoluminescence Developed 3-month old fingerprints | Li et al. (2017) |
| Â | Carbon dots (CD-7) | Hydrothermal | FESEM, FTIR, PL, TEM, XPS, XRD, zeta pot. | 2, spherical quadrilateral | Powder dusting | Glass, plastic | Emit blue fluorescence under 365-nm UV light | An eco-friendly and cost-effective synthesis | Li et al. (2018) |
|  | Starch-based carbon dots (CD-1) | Pyrolysis | UV-Vis, XRD, FT-IR, TEM, fluorescence spectra | 10–40 nm, spherical | Powder dusting | Glass slide, aluminum foil, coin, copper foil, zinc sheet, iron sheet, stain less ruler | Blue fluorescence | Well defined Characteristics for finger ridge | Li et al. (2016) |
|  | Orange carbon dots (CD-15) | Hydrothermal | AFM, CLSM, DLS, FTIR, HRTEM, PL, RS, TEM, UV-Vis, XPS | 15.9 ± 0.6, quasi-spherical | Spraying | Glass | Emit orange fluorescence with 550-nm excitation | Effective, fast, and user-friendly method for fingerprint detection | Li et al. (2019) |
| Â | N-doped carbon dots (CD-12) | Hydrothermal | NMR, PL, TEM, UV-Vis, XPS | 6.5, Spherical | Powder dusting | Plastic bag, steel tweezer | Bright fluorescence signal when excited at 350 nm | Non-toxic, bright fluorescence | Milenkovic et al. (2019) |
| Â | Luminol-doped carbon dots (CD-33) | Hydrothermal method | EDX-SEM, HR-TEM, FTIR, XPS, UV-visible | 12.9 nm | Powder dusting | Glass, coin, costar, plastic | Fluorescence under 395-nm UV | NR | Nugroho et al. (2022) |
| Â | Carbon dots (CD-23) | Hydrothermal | FTIR, PL, TEM, UV-Vis, XPS, zeta pot. | 4, spherical | Transfer | Glass | Emit blue fluorescence under 360-nm UV light | Non-toxic, easy-to-use, water-soluble carbon dots | Pacquiao et al. (2018) |
|  | ZnO-doped N-carbon dots (CD-3) | Hydrothermal | EDX, FTIR, PL, RS, SEM, TEM, UV-Vis, XRD, zeta nanosizer | 20–50 | Powder dusting | Aluminum foil, magazine paper, iron disc, black mat, white marble, compact disc | Emit blue fluorescence under 365-nm UV light | Non-toxic | Prabakaran & Pillay (2020) |
| Â | Nitrogen-doped carbon dots (CD-13) | Solvothermal | FTIR, HRTEM, PL, UV-Vis, XPS | 3.52, spherical | Powder dusting | Silicon wafer | Bright fluorescence signal when excited at 365 nm | Low toxicity, 3rd-level details are visible in developed fingerprints | Ren et al. (2018) |
| Â | d-CDs (CD-28) | Thermal processing | XRD, TEM, EDX, FT-IR, RS, PL, PLE | 10 nm | Powder dusting | NR | UV-light irradiation | Non-toxic, highly luminescent in the deep-blue region, cost-worthy | Savaedi et al. (2022) |
|  | Orange carbon dots (CD-6) | Hydrothermal | FTIR, HRTEM, PL, UV-Vis, XPS | 2.1 ± 0.57, spherical | Droping | Silicon wafer, tape, coin, optical disc, plastic Food package, cardboard, soft drink Paper packaging, meter glass, beer cans | Orange fluorescence with UV light | Non-toxic, fast development, 2nd-level details are visible | Tang et al. (2019) |
| Â | Nitrogen-doped carbon dots (CD-14) | Pyrolysis | DLS, FTIR, PL, TEM, UV-Vis, XPS, zeta pot. | 8 or 20, spherical | Droping | Glass slide | Fluorescence under UV light | Non-toxic, easy to use, water-soluble NCD | Thongsai et al. (2017) |
|  | Carbon dots (CD-20) | Electrochemical | FTIR, HRTEM, PL, RS, UV-Vis, XPS, XRD, zeta pot. | 2.4 ± 0.4, spherical | Spraying | NR | Emit blue fluorescence at 365 nm | Fast and cost-effective method, low toxicity, photostable, water-dispersible carbon dots | Wang et al. (2014) |
|  | Nitrogen- and sulfur-doped solid fluorescent carbon dots (CD-39) | Microwave | AFM, FTIR, NMR, PL, TEM, UV-Vis, XPS, zeta pot. | 2–7 | Powder dusting, spraying | Aluminum, foil, glass, plastic, steel, paper, ceramic | NR | Stable, strong color-tunable fluorescence, 3rd-level details are visible in developed fingerprints | |
|  | Carbon dots (CD-18) | Microwave or pyrolysis | FTIR, HRTEM, PL, TEM, UV-Vis, XPS XRD | 3.2–7.8, spherical | Powder dusting | Glass, plastic, tin foil, weighing paper | Emit green-yellow fluorescence under 365-nm UV light | Self-quenching-resistant, tunable, solid-state fluorescence | |
| Â | Carbon dots (CD-38) | Pyrolysis | FM, FTIR, HRTEM, PL, RS, SEM, UV-Vis, XPS, XRD | 3.36, spherical | Dropping | Glass, aluminum sheet, stainless steel, polypropylene film, carnelian | Emit blue fluorescence under 365-nm UV light | Non-toxic, photostable, tunable fluorescence | |
| Â | P-carbon dots (CD-26) | Hydrothermal | FTIR, HRTEM, PL, SEM, UV-Vis, XRD, Zeta Pot. | 6, spherical | Powder dusting | Desk, reagent bottle cap, and coin | Emit violet-blue fluorescence under 365-nm UV light | Non-toxic, chemically stable | Wang et al. (2019) |
|  | Grain-doped carbon dots (CD-31) | Hydrothermal | XRD, XPS, TEM, UV, PL | 2–25 nm, spherical | Powder dusting | Glass slide, aluminum foil, cigarette packs, mouse | 365-nm UV light developed by R-dots | High sensitivity and wider applicability, simple, low-cost, low toxicity | Wang et al. (2020) |
| Â | SSF-emitting CD (CD-29) | Microwave | PL, FT-IR, XPS | NR | Powder dusting | Paper currency, coin, steel ruler, tinfoil | Blue fluorescence under 395 nm | NR | Wang et al. (2021) |
| Â | S-R-CD S-O-CD S-Y-CD (CD-30) | Solvothermal method | XPS, TEM, HRTEM, XRD, UV-Vis | 7.8, 6.0, and 3.5 nm Spherical | Powder dusting | Glass slide, ceramic tile, painted wood, aluminum alloy plate, banknote | NR | NR | Wang et al. (2022) |
| Â | R-CDs Y-CDs G-CDs (CD-34) | NR | TEM, HR-TEM, XRD, PL, FL, Raman spectra, XPS, FT-IR, UV-Vis | 4.35 nm, 4.12 nm, and 3.51 nm, respectively | NR | Glass slide | Red, yellow, and green | High contrast of fluorescent signals | Xu et al. (2023) |
|  | Carbon dots (CD-25) | Microwave | FTIR, HRTEM, PL, TEM, UV-Vis, XPS, XRD | 1.5 ± 0.3, spherical | Powder dusting | Glass, tin foil, plastic, weighing paper, coin, reagent bottle cap, desk | Emit bright yellow-green solid-state fluorescence under 365-nm UV light | Rapid synthesis, tunable fluorescence, no background fluorescence interferences | Xu et al. (2014) |
|  | Titanium dioxide-doped carbon dots (CD-36) | Hydrothermal | EDX, FTIR, HRTEM, PL, RS, SEM, TEM, UV-Vis, XRD | 2–5, spherical | Powder dusting | Glass, aluminum foil, marble, mica sheet | NR | Non-toxic, thermally stable, 3rd-level details are visible | Yadav et al. (2018) |
| Â | Cdots@PGV (CD-27) | Microwave | UV, PL, XRD, FT-IR, SEM, HR-TEM | 6 nm, spherical | Powder dusting | Glass slides, painted metal, plastic products, stainless steel | Violet-blue fluorescence under UV irradiation (365 nm) | Low toxicity, recommended to work in a well-ventilated room, or upwind | Yu and Yan (2017) |
| Â | Green carbon dots (CD-21) | Microwave | EDX, FTIR, HRTEM, PL, SEM, UV-Vis, XPS, XRD, ZP | NR | Powder dusting | Glass, tin foil, plastic | Emit green fluorescence under UV light | Low toxicity, excellent thermal and photo stability | Zhai et al. (2019) |
| Â | Silica-based carbon dots (CD-37) | Pyrolysis | DLS, FTIR, PL, TEM, UV-Vis | 141, spherical; DLS = 1.8-nm centered at particle size | Powder dusting | Aluminum foil, glass, plastic bags, leather, drug packings | 415-nm excitation with yellow filter | Non-toxic, tunable fluorescence, high sensitivity, reduce background interference | Zhao et al. (2017) |
| Â | Green-emitting carbon dots (CD-4) | Hydrothermal | FTIR, PL, UV-Vis, XPS | NR | Immersion | Glass, tin foil, transparent tape, sealing bag | Emit green fluorescence under 365-nm UV light | NR | Zhao et al. (2018) |