Nanjing Normal University

Protein condensates, formed through liquid-liquid phase separation (LLPS), are implicated in various diseases including neurodegenerative disorders, cancer, and cardiovascular diseases. Despite the significance of protein condensates, the mechanisms governing their formation and microenvironmental properties remain insufficiently understood due to the lack of effective analytical tools. In this review, we explore the detection techniques and underlying mechanisms related to protein condensates, focusing on key microenvironmental properties such as viscosity, polarity, and pH. The influence of phase separation on these microenvironmental factors and its role in protein aggregation are explored. We also discuss current methods for protein labeling and imaging, comparing their advantages and limitations, and highlight their applications in live-cell studies. This review provides a comprehensive understanding of the factors influencing protein condensate dynamics and their relevance in disease, aiming to advance the development of targeted therapeutic strategies for condensate-related disorders.

Laser-induced breakdown spectroscopy (LIBS) models are extensively utilized for rapid elemental measurements in various scientific and industrial applications. However, elemental differences in different matrices can cause huge deviations in the captured spectra, constituting a major bottleneck for the wide application of LIBS technique. Therefore, we proposed an innovative fusion method named acoustic-optical spectra fusion laser induced breakdown spectroscopy (AOSF-LIBS) to compensate the spectral deviations due to LIBS matrix effects. Based on the standard spectral intensity calculation model, five main factors affected by the spectral difference of the matrix were analyzed, and the deviation between the ideal spectrum and the actual spectrum was calculated. Subsequently, the acoustic signals were transformed from the time domain (LIPA) to the time-frequency domain (acoustic spectrogram) to fully characterize the time-frequency evolution of the rapidly varying pressure wave generated by the plasma. Extract energy and area information from the acoustic spectrogram to characterize the total number density and plasma acquisition direction length. Fusing them with the plasma temperature, electron number density, and elemental interference calculated from the LIBS spectra, a spectral deviation mapping model was established to compensate the spectral deviation caused by matrix effect. To verify the wide adaptability of AOSF-LIBS, the spectral deviations of four matrices, including aluminum, iron, titanium, and nickel matrices, is corrected. After being compensated by AOSF-LIBS, the R² were all improved to more than 0.98, and the root mean square error (RMSE), mean absolute percentage error (MAPE), and relative standard deviation (RSD) of the training set decreased dramatically by 11.42 %, 42.33 % and 3.22 % on average, and those of the test set decreased by 11.40 %, 41.13 and 2.84 % on average. And the ablation study was conducted to verify the contribution of the acoustic signal in the deviation compensation model. The experimental results show that AOSF-LIBS can effectively compensate the spectral deviations of different matrices and realize high-precision elemental quantitative measurement. Therefore, AOSF-LIBS is expected to further promote the application of LIBS for elemental quantification.

Fluorescent probes offer a promising approach to detecting and imaging biologically essential copper (Cu²⁺) and sulfide (S^2-) ions, which play critical roles in various physiological processes. However, many existing Cu²⁺ and S^2- probes have limitations like narrow Stokes shifts. To address this, we rationally designed and synthesized three quinoline-based fluorescent probes (CuQP-1, CuQP-2, and CuQP-3), each incorporating a unique Cu²⁺ ion recognition group. Notably, CuQP-1 exhibited a substantial Stokes shift of 178 nm. Furthermore, CuQP-1 displayed selective fluorescence quenching upon interaction with Cu²⁺ ions, which was uniquely restored upon the subsequent addition of S^2- ions. Subsequent investigations revealed that CuQP-1 can effectively image Cu²⁺ and S^2- ions in HT22 cells and zebrafish, underscoring its potential as a versatile tool for studying these analytes in biological systems. In addition, the [CuQP-1 + Cu²⁺] complex is suitable for S^2- detection in real samples.