Laser-Shock-Driven In Situ Evolution of Atomic Defect and Piezoelectricity in Graphitic Carbon Nitride for the Ionization in Mass Spectrometry

• Published in: ACS nano Vol. 16; no. 11; pp. 18284 - 18297
• Main Authors: Kim, Moon-Ju, Noh, Joo-Yoon, Yun, Tae Gyeong, Kang, Min-Jung, Son, Dong Hee, Pyun, Jae-Chul
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 22.11.2022
• Subjects: Graphite - chemistry; Lasers; Reproducibility of Results; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization - methods; atomic defect; LDI-MS; piezoelectricity; laser-induced shock wave; 2D g-C3N4 nanosheets; anisotropic lattice distortion
• DOI: 10.1021/acsnano.2c05993
• ISSN: 1936-0851

Nanostructurescoupled with mass spectrometryhave been intensively investigated to improve the detection sensitivity and reproducibility of small biomolecules in laser desorption/ionization mass spectrometry (LDI-MS). However, the impact of laser-induced shock wave on the ionization of the nanostructures has rarely been reported. Herein, we systematically elucidate the laser shock wave effect on the ionization in terms of the in situ development of atomic defects and piezoelectricity in two-dimensional graphitic carbon nitride nanosheets (g-C3N4 NS) by short laser pulses. The mass analysis results of immunosuppressive drugs verify the enhanced LDI-MS performance, structurally originating from anisotropic lattice distortions in g-C3N4 NS, i.e., in-plane extension (contraction) and out-of-plane contraction (extension) that modulate the charge carrier motion. Along with the experimental investigations, density functional theory calculations on Mulliken charges and dipole moments demonstrate the contribution of defect and piezoelectricity to the ionization. The results of this study provide a mechanistic understanding of the underlying ionization processes, which is crucial for revealing the full potential of laser shock waves in LDI-MS.