Surface-enhanced Raman spectroscopy (SERS) is an extremely powerful analytical tool, which not only yields information about the molecular structure of the analyte in the form of characteristic vibrational spectrum but also gives sensitivities approaching those in fluorescence spectroscopy. The SERS measurement on the microfluidic platform provides possibility to manufacture the device with design perfectly fulfilling the needs of the application with minimal sample consumption. This review aims at describing basic strategies for SERS measurement in microfluidic devices published in the last decade and covers current trends in microfluidics with SERS detection in the field of bioanalysis and approaches toward on-line coupling of liquid-based separation techniques with SERS detection.

• Klíčová slova
• Microfluidics, Nanoparticles, Separation, Surface-enhanced Raman spectroscopy,
• MeSH
• DNA analýza   MeSH
• fyzikální jevy MeSH
• kovové nanočástice chemie   MeSH
• limita detekce MeSH
• mikrofluidní analytické techniky metody   MeSH
• povrchové vlastnosti MeSH
• proteiny analýza   MeSH
• Ramanova spektroskopie metody   MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• DNA MeSH
• proteiny MeSH

Arsenic of natural or industrial origin often occurs in water and makes it impotable. Due to its high toxicity, very sensitive detection is required. In the present study an ultra-sensitive arsenite (As3+) sensing is reported, based on aggregation-aided surface-enhanced Raman scattering (AA-SERS) of modified silver colloids. SERS intensity of mercapto-compounds attached to the colloidal silver nanoparticles surface is greatly increased in the presence of arsenic. Colloid aggregation is facilitated by cross-linking; a meshwork consisting of arsenic atoms and glutathione bridges is formed, as indicated by UV-Vis absorption spectroscopy, TEM and Raman imaging. The best 2-mercaptopyridine reporter molecule makes it possible to directly detect As3+ at concentrations as low as 0.5 ppb, which is better than achieved by the SERS technique so far.

• Klíčová slova
• Arsenic detection, Colloid cross-linking, Silver nanoparticles, Surface-enhanced Raman scattering,
• MeSH
• arsen * MeSH
• kovové nanočástice * MeSH
• Ramanova spektroskopie MeSH
• stříbro MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• arsen * MeSH
• colloidal silver MeSH Prohlížeč
• stříbro MeSH

Surface-enhanced Raman spectroscopy is a constantly developing analytical method providing not only high-sensitive quantitative but also qualitative information on an analyte. Thus, it is reasonable that it has been tested as a promising detection method in column separations. Although its implementation in analytical separations is not widespread, some surprising results, like enormous signal enhancement and demonstrations of single-molecule identifications, proved in only a few special examples, indicate the potential of the method. The high detection sensitivity and selectivity would be of paramount importance in trace analyses of biologically relevant molecules in complex matrices. However, the combination of surface-enhanced Raman spectroscopy with column separation methods brings two principal issues. Interactions of analytes with metal substrates can cause deteriorations of separations and the detection can be affected by background electrolytes or elution agents. Thus, in principle, this review is on the experimental and methodological solutions to these problems. First, theoretical and practical aspects of Raman scattering, and excitation of surface plasmon in colloid suspensions of nanoparticles and on planar nanostructured substrates are briefly explained. Advances in experimental arrangements of on-line and at-line couplings with column liquid phase separation methods, including microfluidic devices, are described together with chosen analytical applications.

• Klíčová slova
• capillary electrophoresis, coupling, liquid chromatography, nanoparticles, surface-enhanced Raman spectroscopy,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Optofluidics, a research discipline combining optics with microfluidics, currently aspires to revolutionize the analysis of biological and chemical samples, e.g., for medicine, pharmacology, or molecular biology. In order to detect low concentrations of analytes in water, we have developed an optofluidic device containing a nanostructured substrate for surface enhanced Raman spectroscopy (SERS). The geometry of the gold surface allows localized plasmon oscillations to give rise to the SERS effect, in which the Raman spectral lines are intensified by the interaction of the plasmonic field with the electrons in the molecular bonds. The SERS substrate was enclosed in a microfluidic system, which allowed transport and precise mixing of the analyzed fluids, while preventing contamination or abrasion of the highly sensitive substrate. To illustrate its practical use, we employed the device for quantitative detection of persistent environmental pollutant 1,2,3-trichloropropane in water in submillimolar concentrations. The developed sensor allows fast and simple quantification of halogenated compounds and it will contribute towards the environmental monitoring and enzymology experiments with engineered haloalkane dehalogenase enzymes.

• Klíčová slova
• 1,2,3-trichloropropane, Klarite 312, chloroalkane, microfluidics, surface enhanced Raman spectroscopy,
• Publikační typ
• časopisecké články MeSH

Oxidative stress may cause extended tyrosine posttranslational modifications of peptides and proteins. The 3-nitro-L-tyrosine (Nit), which is typically formed, affects protein behavior during neurodegenerative processes, such as Alzheimer's and Parkinson's diseases. Such metabolic products may be conveniently detected at very low concentrations by surface enhanced Raman spectroscopy (SERS). Previously, we have explored the SERS detection of the Nit NO2 bending vibrational bands in a presence of hydrogen chloride (Niederhafner et al., Amino Acids 53:517-532, 2021, ibid). In this article, we describe performance of a new SERS substrate, "pink silver", synthesized photochemically. It provides SERS even without the HCl induction, and the acid further decreases the detection limit about 9 times. Strong SERS bands were observed in the asymmetric (1550-1475 cm-1) and symmetric (1360-1290 cm-1) NO stretching in the NO2 group. The bending vibration was relatively weak, but appeared stronger when HCl was added. The band assignments were supported by density functional theory modeling.

• Klíčová slova
• Nitration, Oxidative stress, Photochemical synthesis, Posttranslational protein modification (PTM), Silver colloids, Surface enhanced Raman spectroscopy (SERS),
• MeSH
• oxid dusičitý MeSH
• peptidy MeSH
• proteiny MeSH
• Ramanova spektroskopie * metody   MeSH
• stříbro * chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• oxid dusičitý MeSH
• peptidy MeSH
• proteiny MeSH
• stříbro * MeSH

Currently, trace detection of drugs, medicinal products, psychoactive substances, poisons and other natural or synthetic compounds in the human body has become one of the most important areas of interest in medicine, toxicology and forensic research. Due to the rapid development of nanotechnology, applications in forensic and biological sciences, food industry and art preservation there is an increasing interest in surface-enhanced Raman scattering (SERS) spectroscopy as a technique capable of low detection limits in the analysis of small amounts of studied analytes. In this study, different excitation wavelengths (785 nm and 1064 nm) were used to find the appropriate experimental conditions for the detection and identification of medically significant alkaloids - atropine and pergolide - by means of surface-enhanced Raman scattering spectroscopy. SERS spectra of selected alkaloids were measured in the concentration range 10-3-10-9 mol∙L-1 using large-scaled platinum substrates coated with electrochemically prepared gold or silver SERS-active layers. Identification was based on the assignment of surface-enhanced characteristic vibrational bands using theoretical (DFT) calculations and comparing them with normal (non-enhanced) Raman spectra of pure compounds. All sets of spectral data were subjected to multivariate statistical approach (partial least squares regression) aiming at prediction of alkaloids concentration in developed models and its comparison with experimental results.

• Klíčová slova
• Atropine, Gold substrates, Pergolide, Raman spectroscopy, SERS, Silver substrates,
• MeSH
• adjuvancia anestetická analýza   MeSH
• agonisté dopaminu analýza   MeSH
• atropin analýza   MeSH
• metoda nejmenších čtverců MeSH
• pergolid analýza   MeSH
• Ramanova spektroskopie metody   MeSH
• stříbro chemie   MeSH
• zlato chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adjuvancia anestetická MeSH
• agonisté dopaminu MeSH
• atropin MeSH
• pergolid MeSH
• stříbro MeSH
• zlato MeSH

Gliomas present one of the most prevalent malignant tumors related to the central nervous system. Surgical extraction is still a preferred route for glioma treatment. Nonetheless, neurosurgeons still have a considerable challenge to detect actual margins of the targeted glioma intraoperatively and correctly because of its great natural infiltration. Here we evaluated the possibility of using surface-enhanced Raman spectroscopy to analyze freshly resected brain tissues. The developed method is based on the application of Au@ZrO2 nanosensor. The plasmonic properties of the sensor were first tested on the analysis of Rhodamine 6G, where concentrations down to 10-7 mol/L can be successfully detected. We also compared the performance of the nanosensor with silver plasmonic nanoparticles, where similar results were obtained regarding the reduction of the fluorescence background and enhancement of the intensity of the measured analytical signal. However, application of silver nanospheres led to increased variations in spectral data due to its probable aggregation. Applied ZrO2@Au nanosensor thus dramatically lowers the fluorescence present in the Raman data, and considerably improves the quality of the measured signal. The developed method allows for rapid discrimination between the glioma's periphery and central parts, which could serve as a steppingstone toward highly precise neurosurgery.

• Klíčová slova
• Au nanospheres, Gliomas, Nanomaterials, Raman spectroscopy, SERS, ZrO(2),
• MeSH
• gliom * MeSH
• kovové nanočástice * chemie   MeSH
• lidé MeSH
• nanokuličky * chemie   MeSH
• Ramanova spektroskopie metody   MeSH
• stříbro chemie   MeSH
• zlato chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• stříbro MeSH
• zlato MeSH

Accurate and rapid diagnosis of prosthetic joint infection (PJI) is vital for rational and effective therapeutic management of this condition. Several diagnostic strategies have been developed for discriminating between infected and noninfected cases. However, none of them can reliably diagnose the whole spectrum of clinical presentations of PJI. Here, we report a new method for PJI detection based on magnetically assisted surface enhanced Raman spectroscopy (MA-SERS) using streptavidin-modified magnetic nanoparticles (MNP@Strep) whose surface is functionalized with suitable biotinylated antibodies and then coated with silver nanoparticles by self-assembly. The high efficiency of this approach is demonstrated by the diagnosis of infections caused by two bacterial species commonly associated with PJI, namely, Staphylococcus aureus and Streptococcus pyogenes. The method's performance was verified with model samples of bacterial lysates and with four real-matrix samples of knee joint fluid spiked with live pathogenic bacterial cells. This procedure is operationally simple, versatile, inexpensive, and quick to perform, making it a potentially attractive alternative to established diagnostic techniques based on Koch's culturing or colony counting methods.

• MeSH
• infekce spojené s protézou diagnóza   MeSH
• lidé MeSH
• magnetické jevy * MeSH
• magnetické nanočástice chemie   MeSH
• povrchové vlastnosti MeSH
• Ramanova spektroskopie * MeSH
• streptavidin chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• magnetické nanočástice MeSH
• streptavidin MeSH

The selective detection of phosphorylated molecules is crucial for various biochemical and analytical applications, yet remains challenging due to their weak Raman signals and limited interactions with conventional SERS substrates. This study presents a novel synthesis strategy for bimetallic Ag/FexOynanocomposites with ambition for the improved sensitivity and selectivity of SERS detection for phosphorylated compounds. Our approach successfully integrates alkaline precipitation of iron salts with the reduction of silver cations, overcoming the inherent incompatibility of these processes to produce a stable colloid. The resulting nanocomposites feature an architecture that ensures direct analyte interaction with both components: iron oxides selectively capture phosphorylated molecules, while silver provides plasmonic enhancement of the Raman signal. Our findings highlight the critical role of the silver/iron oxides interface in governing SERS sensitivity. This work represents a significant step toward more effective SERS-based detection strategies, with potential applications in real-time analysis using flow-based systems, such as online monitoring after separation techniques in biochemical and medical fields.

• Klíčová slova
• UV-VIS spectrometry, bimetallic, composite, nanoparticles, phosphorylation, surface-enhanced Raman spectroscopy, synthesis,
• Publikační typ
• časopisecké články MeSH

A fast method for preparing of silver particle layers on glass substrates with high application potential for using in surface enhanced Raman spectroscopy (SERS) is introduced. Silver particle layers deposited on glass cover slips were generated in one-step process by reduction of silver nitrate using several reducing agents (ethylene glycol, glycerol, maltose, lactose and glucose) under ultrasonic irradiation. This technique allows the formation of homogeneous layers of silver particles with sizes from 80nm up to several hundred nanometers depending on the nature of the used reducing agent. Additionally, the presented method is not susceptible to impurities on the substrate surface and it does not need any additives to capture or stabilize the silver particles on the glass surface. The characteristics of prepared silver layers on glass substrate by the above mentioned sonochemical approach was compared with chemically prepared ones. The prepared layers were tested as substrates for SERS using adenine as a model analyte. The factor of Raman signal enhancement reached up to 5·10(5). On the contrary, the chemically prepared silver layers does not exhibit almost any pronounced Raman signal enhancement. Presented sonochemical approach for preparation of silver particle layers is fast, simple, robust, and is better suited for reproducible fabrication functional SERS substrates than chemical one.

• Klíčová slova
• Glass substrate, Silver particles layer, Sonochemical, Surface enhanced Raman spectroscopy,
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH