Sudan III, a synthetic azo dye, is commonly used for coloring oils, waxes, and various plastics. However, its unauthorized presence in food and food products poses serious health hazards, including potential carcinogenic effects. In this study, we investigated the application of nitrogen and sulfur co-doped carbon quantum dots (N,S-CQDs) as a fluorescence sensor to detect trace amounts of sudan III. When exposed to trace amounts of sudan III, the fluorescence signal of N,S-CQDs was significantly enhanced. Under optimal conditions (pH 5.0 and an incubation time of 4 minutes), the fluorescence enhancement of N,S-CQDs showed a linear relationship with sudan III concentration in the range of 7.5 x 10-10 to 1.0 x 10-8 M, with a limit of detection of 2.0 x 10-10 M (equivalent to 0.07 ppb). The method demonstrated high accuracy (recovery from 91.5% to 103.5%), good reproducibility (RSD < 3.86%), and excellent selectivity for sudan III over other azo dyes. We successfully applied this developed method to analyze sudan III in chili sauce and chili powder samples, cross-checking differences between results less than 10% with LC-MS/MS analysis.
carbon quantum dots; sudan III; fluorescence enhancement effect.
[1]. R. A. Pastorok, S. M. Bartell, S. Ferson, and L. R. Ginzburg, "Ecological modeling in risk assessment: chemical effects on populations, ecosystems, and landscapes," CRC Press, 2016.
[2]. Nguyen Thi Minh Huyen, Tran Thi Hoa, Ninh Thi Tuyet Lan, Tran Thi Hien, "Assessment of Listeria monocytogenes, Staphylococcus aureus and Salmonella spp. contamination in dairy samples collected in Gia Lam and Ba Vi, Hanoi," Vietnam Journal of Food Control, vol. 2, no. 4, pp. 22-32, 2019 (in Vietnamese).
[3]. A. Panusa, M. Orioli, G. Aldini, and M. Carini, "A rapid and sensitive LC-ESI-MS/MS method for detection and quantitation of methylprednisolone and methylprednisolone acetate in rat plasma after intra-articular administration," Journal of Pharmaceutical and Biomedical Analysis, vol. 51, no. 3, pp. 691–697, 2010.
[4]. Tran Cao Son, Le Thi Hong Hao, Thai Nguyen Hung Thu, "Determination of pesticide multi-residues in herbal teas using QuEChERS extraction followed by gas and liquid chromatography-tandem mass spectrometry," Conference Proceeding – The 4th analytica Vietnam Conference, Ho Chi Minh City, Ha Noi: Vietnam Analytical Sciences Society (VASS), pp. 196-203, 2015.
[5]. Tran Tan Khoa, "Knowledge and practice of food hygiene and safety and some related factors of people directly preparing food at table-top restaurants in Hong Ngu district, Dong Thap province in 2015," Master's thesis, Hanoi University of Public Health, (In Vietnamese).
[6]. F. Calbiani, M. Careri, L. Elviri, A. Mangia, L. Pistara, I. Zagnoni, "Development and in-house validation of a liquid chromatography–electrospray–tandem mass spectrometry method for the simultaneous determination of sudan I, sudan II, sudan III and sudan IV in hot chilli products," Journal of Chromatography A, 1042 (1-2), 123-130, 2004.
[7]. M. Jahn, S. Patze, T. Bocklitz, K. Weber, D. Cialla-May, J.Popp, "Towards SERS based applications in food analytics: Lipophilic sensor layers for the detection of sudan III in food matrices," Analytica chimica acta, 860, 43-50, 2015.
[8]. M. Heydari, S. M. Ghoreishi, A. Khoobi, "Response surface modeling of electrochemical data for sensitive determination of sudan III in food products at the surface of a nanocomposite modified electrode," Food Analytical Methods, 12, 1781-1790, 2019.
[9]. J. Kowalski, C. V. Bartlett, B. Wittrig, "Analysis of sudan I, sudan II, sudan III and sudan IV using LC UV and LC MS," Food Additives and Contaminants, 21 (10), 935-74, 2004.
[10]. O. Chailapakul, W. Wonsawat, W. Siangproh, K. Grudpan, Y. Zhao, Z. Zhu, "Analysis of sudan I, sudan II, sudan III, and sudan IV in food by HPLC with electrochemical detection: Comparison of glassy carbon electrode with carbon nanotube-ionic liquid gel modified electrode," Food Chemistry, 109 (4), 876-882, 2008.
[11]. Y. Yu, S. Wu, C. Zhang, F. Chen, "Separation and enrichment of sudan III using surface modified hollow glass microspheres and colorimetric detection," Journal of AOAC International, 104 (1), 165-171, 2021.
[12]. C. V. Di Anibal, M. Odena, I. Ruisánchez, M. P. Callao, "Determining the adulteration of spices with sudan I-II-II-IV dyes by UV–visible spectroscopy and multivariate classification techniques," Talanta, 79 (3), 887-892, 2009.
[13]. H. Wang, S. J Jang, Z. Xu, L. Xu, "A novel fluorescent sensor based on a magnetic covalent organic framework-supported, carbon dot-embedded molecularly imprinted composite for the specific optosensing of bisphenol A in foods," Sensors and Actuators B: Chemical, 361, 131729, 2022.
[14]. L. Liu, Q. Huang, Z. I. Tanveer, K. Jiang, J. Zhang, H. Pan, L. Luan, X. Liu, Z. Han, Y. Wu, " “Turn off-on” fluorescent sensor based on quantum dots and self-assembled porphyrin for rapid detection of ochratoxin A," Sensors and Actuators B: Chemical, 302, 127212, 2020.
[15]. Nguyen Quang Khanh, Thi Nguyen Dinh, Pham Thi Mai Anh, et al., "A highly sensitive fluorescence nanosensor for determination of amikacin antibiotics using composites of carbon quantum dots and gold nanoparticles," Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 305, 123466, 2024.
[16]. F. Yuan, S. Li, Z. Fan, X. Meng, L. Fan, S. Yang, "Shining carbon dots: Synthesis and biomedical and optoelectronic applications," Nano Today, 11 (5), 565-586, 2016.
[17]. S. Y. Lim, W. Shen, Z. Gao, "Carbon quantum dots and their applications," Chemical Society Reviews, 44 (1), 362-381, 2015.
[18]. P. G. Luo, S. Sahu, S.-T. Yang, S. K. Sonkar, J. Wang, H. Wang, LeCroy, E. G, L. Cao, Sun, Y.-P, "Carbon “quantum” dots for optical bioimaging," Journal of Materials Chemistry B, 1 (16), 2116-2127, 2013.
[19]. L. Li, G. Wu, G. Yang, J. Peng, J. Zhao, J.-J. Zhu, "Focusing on luminescent graphene quantum dots: current status and future perspectives," Nanoscale, 5 (10), 4015-4039, 2013.
[20]. X. Kou, S. Jiang, S.-J. Park, L.-Y. Meng, "A review: recent advances in preparations and applications of heteroatom-doped carbon quantum dots," Dalton Transactions, 49 (21), 6915-6938, 2020.
[21]. S. D. Dsouza, M. Buerkle, P. Brunet, Maddi, C. Padmanaban, B.D., A. Morelli, A. F. Payam, P. Maguire, D. Mariotti, V. Svrcek, "The importance of surface states in Ndoped carbon quantum dots," Carbon, 183, 1-11, 2021.
[22]. Y. Li, Y. Hu, Y. Jia, X. Jiang, Z. N. Cheng, "S co-doped carbon quantum dots for the selective and sensitive fluorescent determination of N-acetyl-l-cysteine in pharmaceutical products and urine," Analytical Letters, 52 (11), 1711-1731, 2019.
[23]. Y. Wang, J. Lin, Y. Cui, Q. Li, L. Ding, Y. Chen, "Sensitive and Selective Determination of sudan I in Food by Molecularly Imprinted Polymer (MIP) Based Fluorescence Resonance Energy Transfer (FRET)," Analytical Letters, 57 (6), 876-890, 2024.
[24]. M. C. Dos Santos, W. R. Algar, I. L. Medintz, N. Hildebrandt, "Quantum dots for Förster resonance energy transfer (FRET)," TrAC Trends in Analytical Chemistry, 125, 115819, 2020.
[25]. Hong Ngoc Pham, My Hoa Luong, Dinh Thi Nguyen, Quang Khanh Nguyen, Quoc Anh Hoang, Cong Doanh Sai, Thi Dieu Thuy Ung, Bach Pham, Thi Anh Huong Nguyen, Duc Thang Pham, Thi Ngoc Mai Pham "Development of fluorescence nanosensor based on “off-on” effect of graphitic carbon nitride-gold nanoparticles system for amikacin quantification," Materials Chemistry and Physics, 311, 128562, 2024.
[26]. Duy Khanh Nguyen, Quang Trung Le, Xuan Dung Mai, Thanh Son, "The roles of intermediate fluorophores on the optical properties of bottom-up synthesized carbon nanodots," HPU2 Journal of Science: Natural Sciences and Technology, 2(2), 68–82, 2023.
[27]. G. S. Kumar, R. Roy, D. Sen, U. K. Ghorai, R. Thapa, N. Mazumder, S. Saha, K. K. Chattopadhyay, "Amino-functionalized graphene quantum dots: origin of tunable heterogeneous photoluminescence," Nanoscale, 6 (6), 3384-3391, 2014.
[28]. S. Chen, X. Hai, C. Xia, X. W. Chen, J. H. Wang, "Preparation of excitation‐ independent photoluminescent graphene quantum dots with visible‐light excitation/emission for cell imaging," Chemistry–A European Journal, 19 (47), 15918-15923, 2013.
[29]. Q. Liu, N. Zhang, H. Shi, W. Ji, X. Guo, W. Yuan, Q. Hu, "One-step microwave synthesis of carbon dots for highly sensitive and selective detection of copper ions in aqueous solution," New Journal of Chemistry, 42 (4), 3097-3101, 2018.
[30]. AOAC International, "Guidelines for standard method performance requirements," AOAC International Rockville, MD, USA, 2012.