Research data supporting 'Tracking Interfacial Single-molecule pH and Binding Dynamics via Vibrational Spectroscopy'

Research data supporting 'Tracking Interfacial Single-molecule pH and Binding Dynamics via Vibrational Spectroscopy' DOI: DOI: 10.1126/sciadv.abg1790 Figure 1B: Time-averaged SERS spectra of the MPA monolayer collected from SPARK, Nanoparticle-on-mirror (NPoM), and Nanocube-on-mirror (NCoM) nanocavities with, respectively, using 20-μW, 500-μW, and 1.2-mW optical excitation at 633 nm (300 s integration time), together with simulated Raman spectrum for monodentate MPA using polarized DFT calculations. Figure 2: (A) SPARK SERS time series showing single-molecule dynamics of MPA, with 50-ms integration time per spectrum. (B) Pure state experimental spectra (deprotonated, protonated, and monodentate) extracted from SERS time scan. (G) Time evolution of the extracted fractional weights for the three pure states, revealing dynamic switching behavior. DFT spectra are generated through files in the Supplementary Information of the publication. Figure 3: (A) SPARK SERS time series showing single molecular dynamics of MPA salt, with 100-ms integration time. (B) Pure state spectra extracted from the SERS time scan. (G) Full time evolution of a single MPA molecule hopping between three coordination states: unbound, monodentate, and bidentate. Figure 4: (C) Extracted effective single-molecule pH fluctuation showing deprotonation is increasingly favored in time (pKa =4.3). (D) Variation of equilibrium energies of the monodentate (blue) and bidentate (green) states versus the unbound state extracted from the transition kinetics of the MPA salt. (E) Distributions of dwell times in the unbound (UB), monodentate (MD), and bidentate (BD) states of an MPA salt picocavity before hopping to a neighbor state.

支撑论文《通过振动光谱学追踪界面单分子pH与结合动力学》（DOI: 10.1126/sciadv.abg1790）的研究数据。

图1B：分别采用633 nm波长下20 μW、500 μW及1.2 mW的光激发（积分时长300 s），从SPARK、纳米颗粒-镜面（Nanoparticle-on-mirror, NPoM）及纳米立方体-镜面（Nanocube-on-mirror, NCoM）纳米腔中采集得到的巯基丙酸（Mercaptopropionic acid, MPA）单分子层的时间平均表面增强拉曼散射（Surface-Enhanced Raman Spectroscopy, SERS）光谱，同时附带通过极化密度泛函理论（Density Functional Theory, DFT）计算得到的单齿配位MPA的模拟拉曼光谱。

图2：(A) SPARK SERS时间序列，展示了MPA的单分子动力学，每条光谱的积分时长为50 ms。(B) 从SERS时间扫描中提取得到的三种纯态实验光谱（去质子化态、质子化态及单齿配位态）。(G) 三种纯态的提取分数权重随时间的演化过程，揭示了动态切换行为。密度泛函理论光谱由该论文的补充材料中的文件生成。

图3：(A) SPARK SERS时间序列，展示了MPA盐的单分子动力学，积分时长为100 ms。(B) 从SERS时间扫描中提取得到的纯态光谱。(G) 单个MPA分子在三种配位状态（未结合态、单齿配位态及双齿配位态）之间跃迁的完整时间演化过程。

图4：(C) 提取得到的有效单分子pH波动，显示去质子化过程随时间愈发占优（pKa=4.3）。(D) 从MPA盐的跃迁动力学中提取得到的、单齿配位态（蓝色）与双齿配位态（绿色）相对于未结合态的平衡能量变化。(E) 某一MPA盐皮腔（picocavity）在跃迁至相邻状态前，其未结合态（UB）、单齿配位态（MD）与双齿配位态（BD）的驻留时间分布。