A unique "turn-on" fluorescence signalling strategy for highly specific detection of ascorbic acid using carbon dots as sensing probe.
Carbon dots (CDs) that showed strong blue fluorescence were successfully synthesised from sodium alginate via furnace pyrolysis. The single step pyrolytic synthesis was simple to perform while yielded CDs with high photostability, good water solubility and minimum by-products. In order to design the probe with "turn-on" sensing capability, the CDs were screened against a series of metal cations to first "turn-off" the fluorescence. It was found that ferric ions (Fe(3+)) were most responsive and effective in quenching the fluorescence of CDs. Based on this observation, the conditioning of the probe was performed to ensure the fluorescence was completely quenched, while not overloading the system with Fe(3+). At the optimised condition, the CDs-Fe(3+) mixture served as a highly specific detection probe for ascorbic acid (AA). The analytical potential of the probe was evaluated and showed a good linear range of response for AA concentration of 24-40μg/mL. The selectivity study against other possible co-existing species was carried out and proved that our unique "turn-on" fluorescence signalling strategy was highly effective and selective towards AA as the target analyte. The probe was demonstrated for quantification of AA in real samples, which was the commercially available vitamin C supplement. The result showed good accuracy with minimum deviation from standard method adopted for validation purpose.
Swinburne Sarawak Research Centre of Sustainable Technologies, Swinburne University of Technology Sarawak Campus, Jalan Simpang Tiga, 93350 Kuching, Sarawak, Malaysia; Faculty of Engineering, Computing and Science, Swinburne University of Technology Sarawak Campus, Jalan Simpang Tiga, 93350 Kuching, Sarawak, Malaysia.
Jessica Fung Yee
JFY
Fong
Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, 94300 Kota Samarahan, Sarawak, Malaysia.
Suk Fun
SF
Chin
Swinburne Sarawak Research Centre of Sustainable Technologies, Swinburne University of Technology Sarawak Campus, Jalan Simpang Tiga, 93350 Kuching, Sarawak, Malaysia; Faculty of Engineering, Computing and Science, Swinburne University of Technology Sarawak Campus, Jalan Simpang Tiga, 93350 Kuching, Sarawak, Malaysia. Electronic address: smng@swinburne.edu.my.
Sing Muk
SM
Ng
D001205:Ascorbic Acid / Q000032:analysis*; D002244:Carbon / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D019587:Dietary Supplements / Q000032:analysis; D005456:Fluorescent Dyes / Q000737:chemistry*; D007501:Iron / Q000737:chemistry; D057230:Limit of Detection; D045663:Quantum Dots / Q000737:chemistry* / Q000648:ultrastructure; D013050:Spectrometry, Fluorescence / Q000379:methods; D014815:Vitamins / Q000032:analysis*
D002412:Cations; D005456:Fluorescent Dyes; D014815:Vitamins; D002244:Carbon; D007501:Iron; D001205:Ascorbic Acid
Ascorbic acid; Carbon dots; Fluorescence “turn-on”; Optical sensing; Sustainable sensing