Promoting identification of amyotrophic lateral sclerosis based on label-free plasma spectroscopy.

OBJECTIVE: Amyotrophic lateral sclerosis (ALS) is an adult-onset fatal neurodegenerative disease which lacks identified biological markers. A label-free plasma surface-enhanced Raman spectroscopy (SERS) method was developed to explore a simple and noninvasive test for ALS. METHODS: ALS patients were enrolled serially and plasma samples were collected at the time of diagnosis prior to the start of ALS treatment. SERS spectra were recorded using a Renishaw micro-Raman system. RESULTS: To exclude the interference by varying disease severity, we enrolled three groups of ALS patients, including ALS-1 (n = 60; ALSFRS-R ≥ 42 and time interval ≤ 12 months), ALS-2 (n = 61; ALSFRS-R < 42 and time interval ≤ 12 months), and ALS-3 (n = 61; ALSFRS-R ≥ 38 and time interval> 12 months). The SERS spectra were analyzed using principal component analysis (PCA), which showed that ALS-1, ALS-2, ALS-3, and control groups were separated significantly. Then, decision tree (DT) models and receiver operating characteristic curves were employed and identified that bands at 722 and 739 cm-1 , and ratios of 635-722 cm-1 and 635-739 cm-1 were able to distinguish ALS from controls significantly. Finally, we highlighted six metabolism pathways correlated with ALS, including phenylalanine-tyrosine-tryptophan biosynthesis, aminoacyl-tRNA biosynthesis, phenylalanine metabolism, pantothenate and CoA biosynthesis, porphyrin and chlorophyll metabolism, and pyrimidine metabolism. INTERPRETATION: Plasma SERS could be a promising tool for the detection of ALS. The bands at 722 and 739 cm-1 , and the ratios of 635-722 cm-1 and 635-739 cm-1 could serve as potential indicator for ALS.

Prognostic analysis of amyotrophic lateral sclerosis based on clinical features and plasma surface-enhanced Raman spectroscopy.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with a wide range of survival times. We aimed to explore prognostic factors related to short survival based on clinical features and plasma metabolic signatures using surface-enhanced Raman spectroscopy (SERS). One hundred and thirty-eight sporadic ALS cases were enrolled serially, including 62 for the short-duration group (≤3 years) and 76 for the long-duration group (>3 years). Multivariate analysis showed that an older age of onset (>60 years; odds ratio [OR] = 3.98, 95% CI: 1.09-14.53), lower body mass index (BMI) (<18.5; OR = 6.80, 95% CI: 1.36-33.92), and lower ALSFRS-R score (<35; OR = 6.03, 95% CI: 1.42-25.63) were associated with higher odds of tracheotomy or death, while a higher uric acid (UA) level showed a protective effect (>356.36 µmol/L; OR = 0.19, 95% CI: 0.05-0.73). SERS analysis showed significant differences between the two groups, and pathway analysis highlighted five main metabolic pathways, including metabolisms of glutathione, pyrimidine, phenylalanine, galactose, and phenylalanine-tyrosine-tryptophan biosynthesis. In conclusion, age of onset, BMI, ALSFRS-R score and UA, together with dysregulation of glucose, amino acid, nucleic acid, and antioxidant metabolism contributed to disease progression, and are therefore potential therapeutic targets for ALS.

Organometallic-Constructed Tip-Based Dual Chemical Sensing by Tip-Enhanced Raman Spectroscopy for Diabetes Detection.

Tip-enhanced Raman spectroscopy (TERS) is capable of probing specific molecular information with high sensitivity, but dual chemical sensing remains a challenge. Another major hindrance to TERS chemical detection in biosamples such as blood is the interference from the strong absorptions of biomolecules. Herein, we report the preparation of an organometallic-conjugated TERS tip. We demonstrate that organometallic chemistry can be perfectly coupled with TERS for dual-molecule sensing. The unique Raman signals generated by the organometallic compound circumvent signal interference from the biomolecules in blood, allowing the rapid analysis of two important molecules (glucose and thiol) in ultralow volume (50 nL) samples. This enabled a correlation between the thiol and glucose levels in the blood of nondiabetic and diabetic patients to be drawn.

[Advances in Raman Spectroscopy for Nasopharyngeal Carcinoma Tissue].

Nasopharyngeal carcinoma is a unique malignant tumor that has a distinct geographic and racial distribution, with a high incidence in southeast Asia and southern China. High degree of malignancy, poor prognosis and difficulty in early diagnosis remain a problem in nasopharyngeal carcinoma. Raman spectroscopy technique based on inelastic scattering is a rapid and nonivasive detection method, which is capable of providing the information of biochemical components at molecular vibration level.This article reviewed the recent research progress of nasopharyngeal carcinoma based on Raman spectroscopy. It mainly introduces the study of detecting nasopharyngeal carcinoma tissue by using Raman spectroscopy as well as surface-enhanced Raman scattering spectroscopy (SERS). The emphasis is put on the latest works by our research group, including high wavenumber Raman spectroscopy of tissue, Raman spectroscopy of tissue smears, and a specially designed endoscopic device combined with Raman spectroscopy for in vivo nasopharyngeal cancerous tissue detection, which was firstly developed by our group. Finally, the prospects of the development of Raman spectroscopy for nasopharyngeal carcinoma were discussed.

[Studies of Male Fertility with Raman Spectroscopy].

Raman spectroscopy which belongs to scattering spectroscopy obtained molecular vibrational and rotational information to achieve detection and analysis of molecular structure and corresponding changes through recording the frequency shift when light interacted with materials. Compared with routine biochemical analysis, Raman spectroscopy has the advantage of non-invasive, label-free and no sample requirement. Raman spectroscopy has been widely applied in biomedical field such as human tissue, organs, cells and human body fluids for disease diagnosis. This article mainly focuses on recent research advances of Raman spectroscopy in human semen. Firstly, Raman spectroscopy(including surface-enhanced Raman spectroscopy, SERS) employed in forensic science for semen analysis, and some related data processing methods were introduced, then Raman spectroscopy involved investigations of male fertility was highlighted, more specifically, the Raman-based qualitative and quantitative analysis which assist the objective detection and evaluation of male fertility. Furthermore, studies of single sperm cell based on micro-Raman system to characterize and evaluate sperm quality and the preliminarily obtained Raman biomarkers which indicate high-quality sperm cell were introduced. Finally, the potential development of Raman spectroscopy involved in reproduction and fertility field was also discussed.

[Surfaced-Enhanced Raman Scattering Spectroscopic Study on Sheng-Di-Dang-Gui Decoction].

To reveal the relationship between the single decoction and prescription, the surface-enhanced Raman scattering (SERS) spectroscopy of Sheng-Di-Dang-Gui decoction (SDDGD), Sheng-Di decoction (SDD) and Dang-Gui decoction (DGD) were tested and analyzed. Mainly seventeen Raman signals (538, 622, 732, 761, 835, 876, 959, 1 145, 1 245, 1 276, 1 326, 1 402, 1 456, 1 470, 1 518, 1 546 and 1 605 cm(-1)) in three decoctions were discussed. The characteristic Raman bands of three decoctions were tentatively assigned. Fifteen obvious Raman bands (538, 732, 761, 835, 876, 959, 1 145, 1 245, 1 276, 1 326, 1 402, 1 456, 1 470, 1 518 and 1 605 cm(-1)) were observed in the SERS spectroscopy of SDDGD, thirteen obvious Raman bands (538, 761, 835, 876, 959, 1 145, 1 245, 1 276, 1 326, 1 402, 1 470, 1 518 and 1 546 cm(-1)) were observed in the SERS spectroscopy of SDD, ten obvious Raman bands (538, 622, 732, 761, 835, 876, 959, 1 245, 1 326 and 1 402 cm(-1)) were observed in the SERS spectroscopy of DGD. Some Raman bands in SERS spectra of SDD and DGD were retained in the SDDGD, however some Raman bands in two kinds of decoctions never appeared in the SDDGD. And new Raman bands (1 456 and 1 605 cm(-1)) were generated in the SDDGD, resulted in the fact that new chemical compositions were created. Medical ingredients in the SDDGD were not the simple addition of SDD and DGD. The results showed that the SERS spectroscopy might provide a new kind of novel, effective and simple detecting method for the prescription research.

[Preliminary study on the surface enhanced Raman spectrum of tea].

In the present paper, taking Tiegunyin tea as an example, surface enhanced Raman scattering (SERS) spectrum of tea was obtained, the effects of different active substrates were explored from the aspects of enhanced factor, background noise, repeatability, and signal to noise ratio (SNR), while the impact of adsorption time on the measurement was also discussed. The results show that it is feasible to obtain the SERS spectrum of tea, and Raman signal of SERS spectrum was greatly enhanced compared with that of regular Raman spectrum. The active substrate of silver colloid prepared by the reduction of silver nitrate and trisodium citrate has a better enhanced effect, while different adsorption times have no direct influences on the SERS measurement. The method based on SERS firstly proposed in this paper may provide an alternative method for the discriminant analysis and quality identification of tea.

[Surfaced-enhanced Raman spectroscopic study on single living human nasopharyngeal carcinoma cells incubated with colloidal gold].

The surface-enhanced Raman scattering (SERS) spectroscopy and normal Raman spectroscopy of single living human nasopharyngeal carcinoma cells(CNE-1) were tested and analyzed by gold nanoparticles incubation into cells. Six obvious Raman bands (718, 1001, 1123, 1336, 1446 and 1660 cm(-1)) were observed in the normal Raman spectroscopy of living CNE-1 cells. The characteristic Raman bands in the SERS spectra of living cells were tentatively assigned. Colloidal gold particles that were introduced inside cells result in strongly enhanced Raman signals of the native chemical constituents of the cells, and over twenty SERS Raman bands were observed in the SERS spectroscopy of living CNE-1 cells. The Raman lines of 1026, 1097, 1336 and 1585 cm(-1) were assigned to vibrations of the DNA backbone, which confirms that some gold nanoparticles were able to enter the nucleus. The results showed that, based on colloidal gold, the SERS spectroscopy might provide a sensitive and structurally selective detecting method for native chemicals inside a cell, such as DNA and phenylalanine.

[Surface-enhanced raman spectroscopic analysis of largehead Atractylodes rhizome decoction].

The normal Raman spectra and surface-enhanced Raman spectra (SERS) of largehead atractylodes rhizome decoction were tested and analyzed. The characteristic Raman bands of largehead atractylodes rhizome decoction were tentatively assigned. Six obvious Raman bands (396, 548, 617, 730, 955 and 1327 cm(-1)) were observed in the SERS of largehead atractylodes rhizome decoction. The absorption spectra of largehead atractylodes rhizome decoction and the mixture of silver colloids and largehead atractylodes rhizome decoction were tested. A new resonance absorption peak (999 nm) appeared in the long-wavelength region in UV-Vis absorption spectra of the mixture. The adsorption characteristics and possible enhancing mechanism of the largehead atractylodes rhizome decoction on silver colloid were speculated. The results showed that the surface-enhanced Raman spectroscopy might provide a new kind of precise, direct and fast detecting method for the largehead atractylodes rhizome decoction or other traditional Chinese medicine.

[Infrared spectrum analysis of admixture decoction of herba Ephedrae with Ramulus cinnarnomi].

The infrared spectra of decoction of herba ephedra and ramulus cinnarnomi and the mixed decoction of herba ephedra + ramulus cinnarnomi were tested. The change in the mixed decoction was discussed to study the relationship between herba ephedra and ramulus cinnarnomi after decoction. The results showed that some components of herba ephedra and ramulus cinnarnomi were retained in the mixed decoction of herba ephedra + ramulus cinnarnomi, such as 1 205 and 1 074 cm(-1), but some components that never appeared in the two component spectra increased, such as 1 394 and 678 cm(-1). New absorption peaks were generated in the mixed decoction of herba ephedra + ramulus cinnarnomi, such as 757 and 407 cm(-1). It can be showed that there are differences in the chemistry environment of the various chemical groups in the three decoctions introduced above, and with the variation in absorption peak position, possibly some new chemical compositions were created. Medical ingredients in the decoction are not simply the addition of herba ephedra and ramulus cinnarnomi based on the studies of infrared spectrum of the mixed decoction of herba ephedra + ramulus cinnarnomi, and the new notion of prescription spectroscopy was proposed.

[Measurement of nasopharyngeal carcinoma tissue ex vivo by Raman spectroscopy].

Raman spectroscopy has shown its potential and advantages in detecting molecular changes associated with tissue pathology, which makes it possible to diagnose with optical methods non-invasively and real-time. A compact and rapid near-infrared (NIR)Raman system was developed using 785 nm diode laser, volume phase technology (VPT)holographic grating system and NIR intensified charge-coupled device (CCD)with a specially designed Raman fibre probe which can effectively reduce the interference of fluorescence and Rayleigh scattering, maximize the ability of Raman collection as well as correct the image aberration of a planar grating diffraction. Adopting this method, signal-to-noise ratio has been greatly improved and human tissue signals can be acquired in a short time. Raman signals from fat and musculature of fresh pork were measured and referenced for further optimization, then Raman spectra of nasopharyngeal carcinoma in vitro and the effect of storage time on them were measured in 1-5 s and discussed. The sensitivities and performance of the system will be further enhanced and more Raman data will be acquired and compared between normal and cancerous nasopharyngeal tissue, expecting to discover the statistical characteristics, which will benefit the diagnosis and treatment of early nasopharyngeal carcinoma or other tumors.

[Near infrared Raman spectra analysis of rhizoma dioscoreae].

A novel and compact near-infrared (NIR) Raman system was developed using 785 nm diode laser, volume-phase technology holographic system, and NIR intensified charge-coupled device (CCD). The Raman spectra and first derivative spectra of rhizoma dioscoreae were obtained. The Raman spectra of rhizoma dioscoreae showed three strong characteristic peaks at 477, 863 and 936 cm(-1), respectively. The major ingredients are protein, amino acid, starch, polysaccharides and so on, matching the known basic biochemical composition of rhizoma dioscoreae. In the first derivative spectra of rhizoma dioscoreae, the distinguishing characteristic peaks appeared at 467, 484, 870 and 943 cm(-1). Contrasted with rhizoma dioscoreae Raman spectra in the ranges of 600 to 800 cm(-1) and 1 000 to 1 400 cm(-1), the changes in rhizoma dioscoreae Raman first derivative spectra are represented more clearly than the rhizoma dioscoreae Raman spectra. So the rhizoma dioscoreae Raman first derivative spectra can be an accurate supplementary analysis method to the rhizoma dioscoreae Raman spectra.

[Two-photon excitation fluorescence of 5-ALA induced PpIX in DHL cells].

Two-photon fluorescence microscopy is a novel imaging technique, which is primarily sensitive to a specimen's response coming from an in-focus plane, thus has low photo-bleaching and photo-damage to biological samples. 5-ALA induced production of PpIX in DHL cells was excited by 820 nm femtosecond laser; two-photon excitation fluorescence of single cell was obtained in Lambda mode of laser scanning confocal microscope. The specific fluorescence intensity of PpIX which accumulated in DHL cells was measured at 2, 4 and 10 mmol x L(-1) concentration of 5-ALA with different incubation time, which reflected the kinetics of 5-ALA accumulated in DHL cells. Accumulation of PpIX in DHL cells was a dynamic change process. Biphasic alterations of PpIX accumulation were noted: PpIX content enhanced with the increasing time and reached the maximal value around 3 h, however PpIX content decreased in the subsequent incubation time. Results indicate that two-photon fluorescence based on laser scanning microscope can be a useful technology for studying the kinetics of 5-ALA induced PpIX production in DHL cells and other leukemia cells.

[Infrared spectrum analysis of admixture decoction of herba ephedrae with semen armeniacae amarum].

The infrared spectra of decoction of herba ephedra and semen armeniacae amarum and the mixed decoction of herba ephedra + semen armeniacae amarum were tested. The change in the the mixed decoction was discussed to study the relationship between herba ephedra and semen armeniacae amarum after decoction. The results showed that some absorption peaks of herba ephedra and semen armeniacae amarum were retained in the mixed decoction of herba ephedra + semen armeniacae amarum, such as 1402 and 1076 cm(-1), but some absorption peaks that never appear in the two ingredient spectra increased such as 1394 and 682 cm(-1). New absorption peaks were generated in the mixed decoction of herba ephedra + semen armeniacae amarum, such as 688 and 1187 cm(-1). It can be showed that there were differences in the chemistry environment of the various chemical groups in the three decoctions introduced above, with the variation in absorption peak position, and the biochemical structure of the material changed, possibly with some new chemical compositions created. Medical ingredients in the mixed decoction of herba ephedra + semen armeniacae amarum were not simply the addition of herba ephedra and semen armeniacae amarum based on studies of infrared spectrum of decoction, and the new notion of prescription spectroscopy was proposed.

[Research on raman spectra and energy transfer in Tm3+, Ho3+ single and co-doped YVO4 crystals].

Raman spectra of Tm3+ :YVO4, Ho3+ :YVO4 and Tm3+: Ho3+: YVO4 crystals were measured at room temperature by HRD-1 double grating monochromator, with the excitation laser beam were parallel and perpendicular to c axis, respectively. For the Ho3+: YVO4, it was found that the Raman spectrum excited by laser beam perpendicular to axis c is stronger than that by parallel excitation, and because 488 nm laser was very close to the absorption peak of Ho3+, the competition between absorption and scattering results in the 475 cm(-1) Raman mode weakening and external mode widening. It was also found that the most probable phonon energy focused on the 880 cm(-1), which was brought about by the breathe mode of (VO4)3-, Like YAG, YVO4 is a kind of crystal with high phonon energy too. Comparing the luminescence of Tm3+ :YVO4 with that of Tm3+: Ho3+: YVO4, it was found that the intensity of Ho3+ 2.09 microm is about 4/5 of that of Tm3+ 1.85 microm, which means the sensitization efficiency of Tm3+ to Ho3+ was as high as up to 80%, and since the overlap between the luminescence of Tm3+ with the absorption of Ho3+ is quite small, the radiative energy transfer between them was very less possible, and most probability, this process was via the nonradiative, phonon-aided cross-relaxation between Tm3+ and near resonance energy transfer between Tm3+ and Ho3+.

[Spectral properties of the hemoporphyrin derivative interacting with hemoglobin].

The quenching reaction of hemoporphyrin derivative with hemoglobin (Hb) was studied by using fluorescence spectra and absorption spectra. It was shown that HpD has a powerful ability to quench the Hb fluorescence via a nonradiative energy transfer mechanism. The formation constants of them were analyzed at different temperature according to Stern-Volmer equation and double-reciprocal equation, which are bigger at high temperature than at low temperature. The critical binding site was calculated (R0 = 3.22 nm) by Föster energy transfer mechanism, and the thermodynamic parameters were obtained.

[Fourier transform infrared and near-infrared Raman spectra of human red blood cell].

The human red blood cell was studied by Fourier transform infrared and near-infrared Raman spectroscopy.The assignment of the characteristic groups of human red blood cell structure was basically confirmed. At the same time, the authors observed that the intensity of different Raman shift signal has different varying law when the power of laser is changing. Near-infrared laser Raman spectroscopy combined with infrared spectroscopy is an effective method to study the structure of human red blood cell.