拉曼光谱是一种用于分析分子化学成分、结构等信息的检测技术，具有信息丰富、制样简单、水的干扰小、非侵入等特点，在生物医学等研究领域中具有广泛应用。拉曼光谱成像作为一种结合拉曼光谱和成像的混合模式，通过采集空间中每个像素处的拉曼光谱信息，将分子信息在空间上展现，并定性、定量与定位地分析物质分子。相对于传统的拉曼光谱测量，拉曼光谱成像可额外提供生物医学应用中极为重要的空间信息，因此，以图像形式观测物质成分与结构等信息的拉曼光谱成像技术在生物样本检测、临床诊断及治疗等生物医学领域中具有重要的应用价值。从拉曼光谱原理出发,介绍了拉曼光谱成像技术及其发展，并综述了近年来拉曼光谱成像技术在生物医学领域中的应用，最后总结并展望了拉曼光谱成像技术及其发展趋势。

A tunable pulsed laser induced photoacoustic (PA) measurement set-up is established in the forward mode to monitor in vitro glucose concentration. A series of experiments are investigated to verify the feasibility of this set-up and scheme. Peak-to-peak values (PPVs) of several glucose aqueous solutions are recorded and averaged 512 times at each wavelength. Experimental results demonstrate that the time-resolved PA profile of glucose solutions has a good agreement with the PA theories. The characteristic wavelengths of glucose solution are determined via differential method. The root-mean-square error (RMSE) of predicted concentration reaches 3.15 mg/dl at the optimum wavelength of 1 510 nm via least square (LS) fitting algorithm.

We report on the far–infrared optical properties of melamine characterized by terahertz time–domain spectroscopy (THz–TDS). Transmission measurement reveals three low–frequency vibration modes at 1.99, 2.25, and 2.61 THz, which may provide fingerprints for direct melamine detection. By combining THz–TDS with Fourier transform infrared (FTIR) spectroscopy, an overall low–frequency optical response of melamine is presented in an extended spectral range of 0.2–6.2 THz. In this range, the low-frequency vibration mode at 3.96 THz is recorded via FTIR. The measured THz spectra are well fit by the multiple–oscillator model, thereby demonstrating that the low–frequency THz response of melamine is a consequence of the lowest four vibration modes.

Fluorescence lifetime imaging microscopy (FLIM) has gained popularity as a sensitive technique to monitor the functional/conformational states of reduced nicotinamide adenine dinucleotide (NADH), one of the main compounds of oxidative phosphorylation. In this letter, we apply the technique to characterize the metabolic changes in mouse embryonic fibroblast 3T3 cells upon bacterial infection. A gradual shortening of the decaying time constants in both the short and the long lifetime components of NADH’s autofluorescence is detected. The ratio of the short and the long lifetime components’ relative contributions, however, shows a rapid increase, indicating the rise of cellular metabolic activity over the course of infection.

The fluorescence spectra of synthetic food dyes of sunset yellow and tartrazine are analyzed. The fluorescence peak wavelengths of sunset yellow and tartrazine are 576 and 569 nm, respectively, while the fluorescence spectra widths are 480–750 and 500–750 nm induced by ultraviolet light between 310–400 nm. The fluorescence spectra of sunset yellow overlap heavily with those of tartrazine, so it is difficult to distinguish them. Based on the principle of radial basis function neural network, a neural network is obtained from the training of the 14 groups of experimental data. The results show that the species of sunset yellow and tartrazine could be recognized accurately. This method has potential applications in other synthetic food dyes detection and food safety inspection.

To avoid the ill-posedness in the inverse problem of bioluminescence tomography, a moment searching algorithm fusing the finite element method (FEM) with the moment concept in theoretical mechanics is developed. In the algorithm, the source's information is mapped to the surface photon flux density by FEM, and the source's position is modified with the feedback through the algorithm of barycenter searching, which makes full use of the position information of the photon flux density on surface. The position is modified in every iterative step and will finally converge to the real source's value theoretically.

Fluorescence analysis applied in the study of lactic acid bacteria (LAB) provides a new method and theory to study probiotics and realize the detection and identification of the strains. It is also possible to achieve automation and computerization. In this letter, the differences between the fluorescence spectra of lactobacillus casei-BDI (Lc-BDI) and Streptococcus thermophilus (St) are shown, and the second-order derivative spectra are used to further study the diversity of these two strains. According to the results, with the excitation wavelengths of 285 and 340 nm, there are significant differences between them. The experiment is repeated for 6 times, showing good repetitiveness.

Mitoxantrone, a clinically useful antitumour antibiotic for leukaemia and breast cancer, has received more attentions. In this paper, the interaction between mitoxantrone and calf thymus DNA is investigated by Raman and fluorescence spectroscopies, and the binding site of mitoxantrone to calf thymus DNA is explored. The results showed that mitoxantrone interacts with calf thymus DNA bases by the intercalation of anthracycline into the base pair plane of adenine (A) and thymine (T), and it results in the disruption of the hydrogen bonds between calf thymus DNA bases, and thus the calf thymus DNA double-strand can be disrupted into the B-form DNA double-strand segments.

Water-soluble CdTe quantum dots (QD600) were synthesized by hydrothermal route. The uptake of QD600 in living cells of euglena gracilis was studied. The luminescence spectra show that the QD600 were bound in cells after incubation. The fluorescence images, measured by confocal laser scanning microscope, demonstrate that the QD600 can penetrate into the cells. The amount of cell-bound QD600 increased with incubation time of QD600 at 25 Celsius deg., but no detectable QD600 were found in the cells when the incubation temperature was 4 Celsius deg., it was suggested that the QD600 were actively taken into the cells by endocytotic pathway. These results indicate that the water-soluble CdTe quantum dots have the potential in the application of bio-labeling.