Wenqian Yan,Jiayi Yao,Zilin Yue,Hong Lin,Lei Wang,Kaiqiang Wang,Jinjie Li
TVB-N is a commonly used chemical indicator for assessing the freshness of aquatic products during storage. In this study, the combination of Raman spectroscopy with multivariate analysis for monitoring the freshness of sea bass ( Lateolabrax japonicus ) fillets was investigated. Orthogonal signal correction (OSC) method was applied to pre-process the Raman spectra of sea bass fillets with different freshness levels. Results suggested that PLSR models outperformed PCR and SVMR models in monitoring TVB-N values of sea bass fillets. In comparison, the OSC-PLSR model with full-band Raman spectra showed the best performance for predicting TVB-N contents, with R 2 C of 0.981, RMSEC of 1.162 mgN/100 g, R 2 CV of 0.804, RMSECV of 3.756 mgN/100 g, R 2 P of 0.898, RMSEP of 2.199 mgN/100 g, and RPD of 3.824. In addition, sea bass fillets with three different freshness grades (first-grade, second-grade, and spoilage) could be distinguished from the PCA score plot. The PLS-DA model showed an average classification accuracy of 91.11% for different freshness grades. The combination of Raman spectroscopy and chemometrics provided a new tool for the non-destructive evaluation of fish quality.
Sentinel lymph node (SLN) imaging and biopsy has been advocated as an important technique to evaluate the metastatic status of regional lymph nodes and determine subsequent surgical procedure for many cancers, yet there is no reliable means to provide accurate and rapid diagnosis of metastatic SLN during surgery. Here we develop a new approach, named “Ratiometric Raman dual-nanotag strategy”, that using folic acid functionalized targeted and nontargeted gap-enhanced Raman tags (FA-GERTs and Nt-GERTs) to detect metastatic SLN based on Raman imaging combined with classical least square data processing methods. By using this strategy, with built-in self-calibration for signal correction, rather than absolute intensity-dependent signal readout, we realize the visualization and prompt intraoperative diagnosis of metastatic SLN with a high accuracy of 87.5 % when the cut-off value of ratio (FA-GERTs/Nt-GERTs) set at 1.255. This approach may outperform the existing histopathological assessment in diagnosing SLN metastasis and is promising for guiding surgical procedure in the future.
危险品化学品经营许可证（带存储）