Surface-enhanced Raman spectroscopy (SERS) has been shown to be able to detect low-concentration biofluids. Saliva SERS readings of 21 lung cancer patients and 20 normal people were measured and differentiated. Most of the Raman peak intensities decrease for lung cancer patients compared with that of normal people. Those peaks were assigned to proteins and nucleic acids, which indicate a corresponding decrease of those substances in saliva. Principal component analysis (PCA) and linear discriminant analysis (LDA) were used to reduce and discriminate between the two groups of data, and the study resulted in accuracy, sensitivity, and specificity being 80%, 78%, and 83%, respectively. In conclusion, SERS of saliva showed the ability to predict lung cancer in our experiment.

induced fluorescence(LIF) and Raman spectra were measured from normal and tumorous human serum in an attempt to discover some values useful in discrimination between normal and tumorous cases. Red shift of fluorescence peak and decrease of fluorescence intensity were observed after samples radiated by laser. According to one thousand twenty-two samples' spectra, three parameters α, β and δγ are introduced to distinguish normal, benign and malignant from one another. The application of such parameters in clinical diagnosis was researched. The practical instrument of laser-induced serum fluorescence and resonance Raman spectra for cancer diagnosis or incipient cancer is designed, by combining laser spectroscopy, biomedical, photo-electron technology, controlling technology and computer technology. The instrument is intelligent for operating and diagnosing. The clinic application of this instrument has been carried out successfully in the diagnosing of stomach cancer and liver cancer (459 cases); the accuracy is about 85%. It develops a new technology in the field of cancer diagnosis.

In this paper, laser induced human serum Raman spectra of liver cancer are measured. The spectra in serum differences between normal people and liver cancer patients are analyzed. For the typical spectrum of normal serum, there are three sharp Raman peaks and relative intensity of Raman peaks excited by 514.5 nm is higher than that excited by 488.0 nm. However, for the Raman spectrum of liver cancer serum there are no peaks or very weak Raman peaks at the same positions. To liver cirrhosis, the shape of Raman peak is similar to normal and fluorescence spectrum is similar to that of liver cancer from statistic data. The results from more than two hundred case measurements show that the spectral diagnosis was in good agreement with the clinical result. Moreover, the liver fibrosis and liver cirrhosis were studied using the technology of LIF. The experiment indicates that the blue shift of fluorescence peak difference between the normal, liver fibrosis and liver cirrhosis were observed. These results have important reference values to explore the method of laser spectrum diagnosis.

laser induced auto-fluorescence and Raman spectra of serum from cancerous and normal people are measured and analyzed .The content of -carotene ( f3 -BC)m the serum from normal man is higher than that from the cancerous one ,this result agrees with other reports. INTREDUCTIONLaser induced fluorescence spectroscopy and Raman spectroscopy are two kinds of optical tools to be used to probe the molecular structure and contents .It is well known that big biological molecules chromophores such as protein , flavins, riboflavins and porphyrins can display well-defined visible fluorescence spectroscopy with Raman spectroscopies are very sensitive to the microenvironment ofpH ,redox potential ,bonding sites ,polarity ,ion concentration et [1], one can revdal the differcence in the physical snd chemical properties between the health and abnormal blood serum.Resonance Raman scattering can enhance strongly certain vibrational modes of chromophores because it involves transitions with the electonic absorption band of the chromophores when the induced laser wavelength approach the electronic absorption band.In the late 1950's andearly 1960's ,fluoresvence spectrum technology was widely used in the majority of the molecular system of tissues . In the early 1980's ,laser induced fluorescence spectrum form normal and malignant tissues was measured and analyzed by R.R.Alfanl et al [2][3],and the difference ofthe spectroscopies form the two kinds oftissues was also used to diagnose the cancerous tissues ,which normal tissue exhibited Raman spectra on fluorescence spectrum. Because the difference between malignant cancer tissues and normal tissues ,when the metabolic end product of cancer cells go into blood by circulation ,the components and contents of the bioloical molecules and their local environment will be changed.In this paper ,the blood serum fluorescense spectroscopy from normal men and malignant patients is studied and analyzed .The results obtained by the laser induced native fluorescence and Raman spectroscopy reveal instrinsic difference between normal serum and cancerous serum .This new method may be a promising technology for diagnosing cancer from serum spectra. METHODS AND MATERIALSThe experimenal arrangement used to measure the fluorescence and Raman spectra from normal serum samples and malignant serum samples is shown in Fig. I . Anargon ion laser beam at 5 14.5nm was focused into the serum sample .The fluorescence signal from the serum was collected and focused into the entrance slit of a double 0.5-rn grating scanning spectrometer(HRD-1)blazed at SOOnm .A photo multiplier tube (PM;R456 Japen)located at the exit slit of the spectrometer measured the intensity at different wavelengths in scanning .The output signal of PMT was sent to a lock-in amplifier(U.S Model 391)and an XY recorder combination to display the stable spectrum when measuring .The spectra were not calibrated for spectral response of the system .The laser power was about 100mW and laser was chopped at 700Hz .The spectral resolution was about 2nm. ...

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