Water-soluble, biocompatible, and highly luminescence carbon quantum dots (CQDs) have synthesized successfully from a citric acid (CA) and ethylenediamine (EDA) by using different approaches. Although the emission quantum yield of CQDs could be as high as 80% their emission spectrum is usually dominated by surface fluorophore groups and maximized at about 450 nm. Herein, we examined the effects of acid and amine precursors on the photoluminescence (PL) of resulting CQDs by systematic comparison the optical properties of CQDs obtained from CA, PA (phthalic acid) and EDA, ANL (aniline). UV-vis and PL spectroscopic studies revealed that the absorption onset varied from 325 nm to 400 nm while PL maximum changed from 390 nm to 450 nm by engineering acid and amine precursors. The emission quantum yield was also changed from 9 to 70%, depending on the used acid-amine precursors.  Keywords Carbon quantum dots, hydrothermal synthesis, color tuning, photoluminescence, acid, amine References K. Wang, Z. Gao, G. Gao, Y. Wo, Y. Wang, G. Shen, D. Cui, Systematic safety evaluation on photoluminescent carbon dots, Nanoscale Res. Lett. 8 (2013) 1–9. doi:10.1186/1556-276X-8-122.[2] K. Jiang, S. Sun, L. Zhang, Y. Lu, A. Wu, C. Cai, H. Lin, Red, Green, and Blue Luminescence by Carbon Dots: Full-Color Emission Tuning and Multicolor Cellular Imaging, Angew. Chemie Int. Ed. 54 (2015) 5360–5363. doi:10.1002/anie.201501193.[3] M.X. Dung, P. Mohapatra, J.K. Choi, J.H. Kim, S. Jeong, H.D. Jeong, InP quantum dot-organosilicon nanocomposites, Bull. Korean Chem. Soc. 33 (2012) 1491–1504. doi:10.5012/bkcs.2012.33.5.1491.[4] X. Mai, Q. Hoang, The Large-Scale Synthesis of Vinyl-Functionalized Silicon Quantum Dot and Its Application in Miniemulsion Polymerization, J. Nanomater. 2016 (2016).[5] M.X. Dung, D.D. Tung, S. Jeong, H.D. Jeong, Tuning optical properties of Si quantum dots by ??-conjugated capping molecules, Chem. - An Asian J. 8 (2013) 653–664. doi:10.1002/asia.201201099.[6] M.X. Dung, H.D. Jeong, Synthesis of styryl-terminated silicon quantum dots: Reconsidering the use of methanol, Bull. Korean Chem. Soc. 33 (2012) 4185–4187.doi:10.5012/bkcs.2012.33.12.4185.[7] V.-T. Mai, N.H. Duong, X.-D. Mai, Surface Polarity Controls the Optical Properties of One-Pot Synthesized Silicon Quantum Dots, Chem. Phys. (2018).doi:10.1016/j.chemphys.2018.11.012.[8] V.-T. Mai, Q. Hoang, X. Mai, Enhanced Red Emission in Ultrasound-Assisted Sol-Gel Derived ZnO/PMMA Nanocomposite, Adv. Mater. Sci. Eng. 2018 (2018) 1–8. doi:10.1155/2018/7252809.[9] J. Schneider, C.J. Reckmeier, Y. Xiong, M. Von Seckendorff, A.S. Susha, P. Kasak, A.L. Rogach, Molecular fluorescence in citric acid-based carbon dots, J. Phys. Chem. C. 121 (2017) 2014–2022. doi:10.1021/acs.jpcc.6b12519.[10] F. Ehrat, S. Bhattacharyya, J. Schneider, A. Löf, R. Wyrwich, A.L. Rogach, J.K. Stolarczyk, A.S. Urban, J. Feldmann, Tracking the Source of Carbon Dot Photoluminescence: Aromatic Domains versus Molecular Fluorophores, Nano Lett. 17 (2017) 7710–7716. doi:10.1021/acs.nanolett.7b03863.[11] M. Shamsipur, A. Barati, A.A. Taherpour, M. Jamshidi, Resolving the Multiple Emission Centers in Carbon Dots: From Fluorophore Molecular States to Aromatic Domain States and Carbon-Core States, J. Phys. Chem. Lett. 9 (2018) 4189–4198. doi:10.1021/acs.jpclett.8b02043.[12] T.H.T. Xuan-Dung Mai, Quang-Bac Hoang, Hong Quan To, Phuong Le Thi, The synthesis of highly luminescent carbon quantum dots, (2017) (47)20-26.[13] M.X.D. Lê Thị Phượng, Lê Quang Trung, Đỗ Thị Thu Hòa, Doãn Diệu Thúy, Ảnh hưởng của tỷ lệ Acid/Amine đến cấu trúc bề mặt và hiệu suất phát xạ của chấm lượng tử carbon, (2018) (55) 67-74.[14] M.V.T. Hoàng Quang Bắc, Trần Thu Hương, Đinh Thị Châm, Nguyễn Thị Loan, Nguyễn Thị Quỳnh, Bùi Thị Huệ, Lê Thị Thùy Hương, Mai Xuân Dũng, Nghiên cứu tổng hợp hạt nano huỳnh quang từ một số rau củ quả, (2017) 4(40), 70-73.[15] Y. Song, S. Zhu, S. Zhang, Y. Fu, L. Wang, X. Zhao, B. Yang, Investigation from chemical structure to photoluminescent mechanism: a type of carbon dots from the pyrolysis of citric acid and an amine, J. Mater. Chem. C. 3 (2015) 5976–5984. doi:10.1039/C5TC00813A.[16] T.H. Ngà, B.T. Hạnh, M.X. Dũng, Tính toán lượng tử làm rõ tính chất quang học của chấm lượng tử carbon, Tạp Chí KHoa Học - Đại Học Sư Phạm Hà Nội 2. 56 (2018).[17] S. Zhu, Q. Meng, L. Wang, J. Zhang, Y. Song, H. Jin, K. Zhang, H. Sun, H. Wang, B. Yang, Highly photoluminescent carbon dots for multicolor patterning, sensors, and bioimaging, Angew. Chemie - Int. Ed. 52 (2013) 3953–3957. doi:10.1002/anie.201300519.[18] Q.-B. Hoang, V.-T. Mai, D.-K. Nguyen, D.Q. Truong, X.-D. Mai, Crosslinking induced photoluminescence quenching in polyvinyl alcohol-carbon quantum dot composite, Mater. Today Chem. 12 (2019) 166–172. doi:10.1016/j.mtchem.2019.01.003.