title: Real-time analysis of self-assembled nucleobases by Venturi easy ambient sonic-spray ionization mass spectrometry.
abstract: In this study, the real-time analysis of self-assembled nucleobases was employed by Venturi easy ambient sonic-spray ionization mass spectrometry (V-EASI-MS). With the analysis of three nucleobases including 6-methyluracil (6MU), uracil (U) and thymine (T) as examples, different orders of clusters centered with different metal ions were recorded in both positive and negative modes. Compared with the results obtained by traditional electrospray ionization mass spectrometry (ESI-MS) under the same condition, more clusters with high orders, such as [6MU7+Na](+), [6MU15+2NH4](2+), [6MU10+Na](+), [T7+Na](+), and [T15+2NH4](2+) were detected by V-EASI-MS, which demonstrated the soft ionization ability of V-EASI for studying the non-covalent interaction in a self-assembly process. Furthermore, with the injection of K(+) to the system by a syringe pumping, the real-time monitoring of the formation of nucleobases clusters was achieved by the direct extraction of samples from the system under the Venturi effect. Therefore, the effect of cations on the formation of clusters during self-assembly of nucleobases was demonstrated, which was in accordance with the reports. Free of high voltage, heating or radiation during the ionization, this technique is much soft and suitable for obtaining the real-time information of the self-assembly system, which also makes it quite convenient for extraction samples from the reaction system. This "easy and soft" ionization technique has provided a potential pathway for monitoring and controlling the self-assembly processes.
authors: Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, PR China.
authors: Na
authors: N
authors: Na
authors: Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, PR China; Xi׳an Gaoxin No. 1 High School, Xi׳an 710065, PR China.
authors: Ruixia
authors: R
authors: Shi
authors: Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, PR China.
authors: Zi
authors: Z
authors: Long
authors: Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, PR China; National Institute of Food and Drug Control, Beijing 100050, PR China.
authors: Xin
authors: X
authors: Lu
authors: Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, PR China. Electronic address: jfb@bnu.edu.cn.
authors: Fubin
authors: F
authors: Jiang
authors: Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, PR China. Electronic address: jinoyang@bnu.edu.cn.
authors: Jin
authors: J
authors: Ouyang
mesh_terms: D002412:Cations / Q000737:chemistry; D007477:Ions / Q000032:analysis / Q000302:isolation & purification; D011188:Potassium / Q000737:chemistry; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013941:Thymine / Q000032:analysis* / Q000302:isolation & purification; D013997:Time Factors; D014498:Uracil / Q000031:analogs & derivatives* / Q000032:analysis* / Q000302:isolation & purification
chemical_list: D002412:Cations; D007477:Ions; D014498:Uracil; C008378:6-methyluracil; D013941:Thymine; D011188:Potassium
keywords: Cations; On-line analysis; Real-time monitoring; Self-assembled nucleobases; Venturi easy ambient sonic-spray ionization mass spectrometry