It's known to that fluorescence imaging is regarded as a powerful technique for data recording and security. However the technology greatly depends on the development of smart luminescent materials. Although some smart materials have been reported for optical data recording and protection devices, most of them are held back from actual applications owing to their low photostability, potential biotoxicity or poor compatibility. Developing new smart luminescent materials from carbon-based nanomaterials to overcome those deficiencies would be very promising.
Recently Dr.QU Songnan's research team from Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP) have realized water-triggered luminescent “nano-bombs” based on supra carbon-nanodots(CDs). With these “nano-bombs”, water-jet printing luminescence patterns and mapping human sweat pore patterns in the supra-carbon-nanodots-coated paper were demonstrated. This paper was published in Advanced Materials (DOI:10.1002/adma.201403635.Impact factor:15.4).
Researchers broadened the scope of CDs to smart supra-CD system, leading to the development of CDs that are partially functionalized with alkyl chains (CD-Ps). The supra-CDs exhibit water-induced enhancement of the photoluminescent behavior owing to the decomposition of the supra-CDs that was induced by water.
Water-induced rapid luminescence is observed in the supra-CD-coated paper. Ink-free printing luminescent paper is fabricated for information storage and encrypted devices , which is compatible with water-jet printing technique.
Application and promise
This novel CD based nanomaterial has also potential application in medicine and forensics. The power of precisely mapping of active sweat pores on a human fingerprint is also demonstrated via the deposition of a ﬁngerprint on the supra-CD-coated paper.
These smart luminescent carbon nanomaterials hold great promise for applications in optical information storage, information security protection, and clinical diagnosis fields.
This work was supported by the the Outstanding Young Scientist Program of CAS and a project of the State Key Laboratory of Luminescence and Applications. (Advanced Materials)
Figure 1 Schematic for the mechanism of the water induced enhanced luminescence.(Image by Dr.QU Songnan)
Figure 2. Photographs of printed image of supra-CDs coated paper using purely water-filling (3ml) and HP 46 tricolour cartridges under daylight (a) and under UV and daylight (b) (Scale bar = 1 cm). c) Photographs of printed image of supra-CDs coated paper only using purely water-filling (3ml) cartridges under a UV lamp (Scale bar = 1 cm).(Image by Dr.QU Songnan)
Figure 3. a) Photograph of a ﬁngerprint image printed on supra-CD-coated paper (Scale bar = 5 mm). b) Fluorescence microscope images of the magniﬁed ﬁngerprint area marked in (a) using a Photoshop programme for a better subsequently superimposed image (Scale bar = 2 mm). c) Superimposed image of contrast-enhanced luminescent dots on a digital ﬁngertip image (Scale bar = 2 mm). d) Magniﬁed image of the marked area in (c) (Scale bar = 0.5 mm). e,f) Two independently printed contrast-enhanced luminescent microscope ﬁngerprint images deposited by same donor. The red (e) and blue (f) coloured images are intentionally generated using a Photoshop programme for comparison purposes (Scale bar = 2 mm). g) Superimposed images displayed in (e) and (f) (Scale bar = 2 mm). h) Magniﬁed image in the marked area in (g) (Scale bar = 0.5 mm).(Image by Dr.QU Songnan)
Figure 4. (a) Schematic for the water-triggered luminescent “nano-bombs” based on supra-CDs; (b) Photographs of printed image of supra-CDs coated paper only using purely water-filling cartridges under a UV lamp; (c) Fluorescence microscope image of a ﬁngerprint image printed on supra-CD-coated paper; (d) Superimposed image of contrast-enhanced luminescent dots on a digital ﬁngertip image.(Image by Dr.QU Songnan)
Key words: Supra-Carbon Nanodots, Nano-bombs, nanomaterial,water-jet printing