Carbon quantum dots (CQDs) doped with phosphorus and nitrogen were prepared via a hydrothermal method starting from citric acid, urea and phosphoric acid in dimethylformamide solution. The size, morphology, surface composition, energy levels, and optical properties of the CQDs were characterized. They show both green down-conversion and up-conversion fluorescence. Ferric ions (Fe3+) are found to quench the fluorescence. Cyclic voltammetry was used to identify the HOMO and LUMO levels of the doped CQDs. The quenching mechanism, as confirmed by energy level calculations and absorption spectra, can be attributed to the selective coordination of Fe3+ by the surface functional groups on the CQDs. This facilitates the photo-induced electron transfer from the CQDs to the d orbitals of Fe3+. The CQDs are shown to be viable fluorescent probes for determination of Fe3+ with high selectivity and sensitivity. The assay has a linear response in the 0.1 μM to 0.9 μM Fe3+ concentration range and a 50 nM as limit of detection (at a S/N ratio of 3).
This is a preview of subscription content, log in to check access.
Buy single article
Instant access to the full article PDF.
Price includes VAT for USA
Subscribe to journal
Immediate online access to all issues from 2019. Subscription will auto renew annually.
This is the net price. Taxes to be calculated in checkout.
Farrera C, Torres Andón F, Feliu N (2017) Carbon nanotubes as optical sensors in biomedicine. ACS Nano 11(11):10637–10643. https://doi.org/10.1021/acsnano.7b06701
James DK, Tour JM (2013) Graphene: powder, flakes, ribbons, and sheets. Acc Chem Res 46(10):2307–2318. https://doi.org/10.1021/ar300127r
Yu J, Fan F-RF, Pan S, Lynch VM, Omer KM, Bard AJ (2008) Spontaneous formation and electrogenerated chemiluminescence of Tris(bipyridine) Ru(II) derivative nanobelts. J Am Chem Soc 130(23):7196–7197. https://doi.org/10.1021/ja801342v
Omer KM, Ku S-Y, Cheng J-Z, Chou S-H, Wong K-T, Bard AJ (2011) Electrochemistry and electrogenerated chemiluminescence of a spirobifluorene-based donor (triphenylamine)−acceptor (2,1,3-Benzothiadiazole) molecule and its organic nanoparticles. J Am Chem Soc 133(14):5492–5499. https://doi.org/10.1021/ja2000825
Omer KM, Ku S-Y, Chen Y-C, Wong K-T, Bard AJ (2010) Electrochemical behavior and electrogenerated chemiluminescence of star-shaped D−A compounds with a 1,3,5-triazine core and substituted Fluorene arms. J Am Chem Soc 132(31):10944–10952. https://doi.org/10.1021/ja104160f
Omer KM, Bard AJ (2009) Electrogenerated chemiluminescence of aromatic hydrocarbon nanoparticles in an aqueous solution. J Phys Chem C 113(27):11575–11578. https://doi.org/10.1021/jp901038h
Baker SN, Baker GA (2010) Luminescent carbon nanodots: emergent nanolights. Angew Chem Int Ed 49(38):6726–6744
Zhou J, Zhou H, Tang J, Deng S, Yan F, Li W, Qu M (2017) Carbon dots doped with heteroatoms for fluorescent bioimaging: a review. Microchim Acta 184(2):343–368
Zhu S, Meng Q, Wang L, Zhang J, Song Y, Jin H, Zhang K, Sun H, Wang H, Yang B (2013) Highly photoluminescent carbon dots for multicolor patterning, sensors, and bioimaging. Angew Chem 125(14):4045–4049
Wang R, Lu K-Q, Tang Z-R, Xu Y-J (2017) Recent progress in carbon quantum dots: synthesis, properties and applications in photocatalysis. J Mater Chem A 5(8):3717–3734
Jiang X, Zhang Z, Mei J, Han D, Xie M, Wang F, Xie E, Han W (2018) Carbon quantum dots based charge bridge between photoanode and electrocatalysts for efficiency water oxidation. Electrochim Acta 273:208–215
Zhang Z, Jiang X, Mei J, Li Y, Han W, Xie M, Wang F, Xie E (2018) Improved photoelectrocatalytic hydrogen generation through BiVO4 quantum-dots loaded on nano-structured SnO2 and modified with carbon quantum-dots. Chem Eng J 331:48–53
Tang Q, Zhu W, He B, Yang P (2017) Rapid conversion from carbohydrates to large-scale carbon quantum dots for all-weather solar cells. ACS Nano 11(2):1540–1547
Iannazzo D, Pistone A, Salamò M, Galvagno S, Romeo R, Giofré SV, Branca C, Visalli G, Di Pietro A (2017) Graphene quantum dots for cancer targeted drug delivery. Int J Pharm 518(1–2):185–192
Hua X-W, Bao Y-W, Wu F-G (2018) Fluorescent carbon quantum dots with intrinsic nucleolus-targeting capability for nucleolus imaging and enhanced cytosolic and nuclear drug delivery. ACS Appl Mater Interfaces 10(13):10664–10677
Ayala P, Arenal R, Rümmeli M, Rubio A, Pichler T (2010) The doping of carbon nanotubes with nitrogen and their potential applications. Carbon 48(3):575–586
Paraknowitsch JP, Thomas A (2013) Doping carbons beyond nitrogen: an overview of advanced heteroatom doped carbons with boron, sulphur and phosphorus for energy applications. Energy Environ Sci 6(10):2839–2855
Gong K, Du F, Xia Z, Durstock M, Dai L (2009) Nitrogen-doped carbon nanotube arrays with high electrocatalytic activity for oxygen reduction. Science 323(5915):760–764. https://doi.org/10.1126/science.1168049
Ping C, Tian-Yuan X, Yu-Hong Q, Shan-Shan L, Shu-Hong Y (2013) A nitrogen-doped graphene/carbon nanotube nanocomposite with synergistically enhanced electrochemical activity. Adv Mater 25(23):3192–3196. https://doi.org/10.1002/adma.201300515
Gu D, Zhang P, Zhang L, Liu H, Pu Z, Shang S (2018) Nitrogen and phosphorus co-doped carbon dots derived from lily bulbs for copper ion sensing and cell imaging. Opt Mater 83:272–278. https://doi.org/10.1016/j.optmat.2018.06.012
Omer KM, Mohammad NN, Baban SO, Hassan AQ (2018) Carbon nanodots as efficient photosensitizers to enhance visible-light driven photocatalytic activity. J Photochem Photobiol A Chem 364:53–58. https://doi.org/10.1016/j.jphotochem.2018.05.041
Omer KM, Mohammad NN, Baban SO (2018) Up-conversion fluorescence of phosphorous and nitrogen co-doped carbon quantum dots (CDs) coupled with weak LED light source for full-spectrum driven photocatalytic degradation via ZnO-CDs nanocomposites. Catal Lett 148:2746–2755. https://doi.org/10.1007/s10562-018-2459-4
Omer KM, Hassan AQ (2017) Chelation-enhanced fluorescence of phosphorus doped carbon nanodots for multi-ion detection. Microchim Acta 184(7):2063–2071
Wang F, Hao Q, Zhang Y, Xu Y, Lei W (2016) Fluorescence quenchometric method for determination of ferric ion using boron-doped carbon dots. Microchim Acta 183(1):273–279
Hola K, Sudolska M, Kalytchuk S, Nachtigallova D, Rogach AL, Otyepka M, Zboril R (2017) Graphitic nitrogen triggers red fluorescence in carbon dots. ACS Nano 11(12):12402–12410
Wu P, Cai Z, Gao Y, Zhang H, Cai C (2011) Enhancing the electrochemical reduction of hydrogen peroxide based on nitrogen-doped graphene for measurement of its releasing process from living cells. Chem Commun 47(40):11327–11329
Liu S, Tian J, Wang L, Zhang Y, Qin X, Luo Y, Asiri AM, Al-Youbi AO, Sun X (2012) Hydrothermal treatment of grass: a low-cost, green route to nitrogen-doped, carbon-rich, photoluminescent polymer nanodots as an effective fluorescent sensing platform for label-free detection of Cu (II) ions. Adv Mater 24(15):2037–2041
Hart JN, May PW, Allan NL, Hallam KR, Claeyssens F, Fuge GM, Ruda M, Heard PJ (2013) Towards new binary compounds: synthesis of amorphous phosphorus carbide by pulsed laser deposition. J Solid State Chem 198:466–474
Liang B, Jiang C, Chen Z, Zhang X, Shi H, Cao Y (2006) New iridium complex as high-efficiency red phosphorescent emitter in polymer light-emitting devices. J Mater Chem 16(13):1281–1286. https://doi.org/10.1039/B515549E
Zhang H, Chen Y, Liang M, Xu L, Qi S, Chen H, Chen X (2014) Solid-phase synthesis of highly fluorescent nitrogen-doped carbon dots for sensitive and selective probing ferric ions in living cells. Anal Chem 86(19):9846–9852. https://doi.org/10.1021/ac502446m
Omer KM, Ku S-Y, Wong K-T, Bard AJ (2009) Green electrogenerated chemiluminescence of highly fluorescent benzothiadiazole and fluorene derivatives. J Am Chem Soc 131(30):10733–10741. https://doi.org/10.1021/ja904135y
Wang R, Wang X, Sun Y (2017) One-step synthesis of self-doped carbon dots with highly photoluminescence as multifunctional biosensors for detection of iron ions and pH. Sensors Actuators B Chem 241:73–79
Shi B, Su Y, Zhang L, Huang M, Liu R, Zhao S (2016) Nitrogen and phosphorus co-doped carbon nanodots as a novel fluorescent probe for highly sensitive detection of Fe3+ in human serum and living cells. ACS Appl Mater Interfaces 8(17):10717–10725
Ananthanarayanan A, Wang X, Routh P, Sana B, Lim S, Kim DH, Lim KH, Li J, Chen P (2014) Facile synthesis of graphene quantum dots from 3D graphene and their application for Fe3+ sensing. Adv Funct Mater 24(20):3021–3026
Qu K, Wang J, Ren J, Qu X (2013) Carbon dots prepared by hydrothermal treatment of dopamine as an effective fluorescent sensing platform for the label-free detection of iron (III) ions and dopamine. Chem Eur J 19(22):7243–7249
The authors would like to thank the ministry of higher education and scientific research in Kurdistan for supporting this work.
The author(s) declare that they have no competing interests.
Electronic supplementary material
About this article
Cite this article
Omer, K.M., Tofiq, D.I. & Hassan, A.Q. Solvothermal synthesis of phosphorus and nitrogen doped carbon quantum dots as a fluorescent probe for iron(III). Microchim Acta 185, 466 (2018). https://doi.org/10.1007/s00604-018-3002-4
- Carbon quantum dots (CQDs)
- Ferric ions
- Phosphorus doping
- Nitrogen doping
- Fluorescent probe
- Photo-electron transfer
- Cyclic voltammetry