Bisphenol A (BpA) is a chemical that is extensively used in common plastic products, such as food and drink containers. It can leach from the plastics and penetrate into the human body, where it acts as an endocrine disruptor with significant risks to human health. In order to minimize the exposure of human populations to BpA, methods for the detection of BpA are needed. In this work, we present a novel surface plasmon resonance (SPR) biosensor for ultrasensitive detection of BpA. Our approach combines a binding inhibition assay with functionalized gold nanoparticles for the enhancement of sensor response. We demonstrate that the developed biosensor enables the detection of BpA in a wide range of concentrations (0.01 to 100,000 ng/mL) with an extremely low limit of detection-5.2 pg/mL.
Surface plasmon resonance microscopy and imaging are optical methods that enable observation and quantification of interactions of nano- and microscale objects near a metal surface in a temporally and spatially resolved manner. This review describes the principles of surface plasmon resonance microscopy and imaging and discusses recent advances in these methods, in particular, in optical platforms and functional coatings. In addition, the biological applications of these methods are reviewed. These include the detection of a broad variety of analytes (nucleic acids, proteins, bacteria), the investigation of biological systems (bacteria and cells), and biomolecular interactions (drug-receptor, protein-protein, protein-DNA, protein-cell).
- MeSH
- Bacteria izolace a purifikace ultrastruktura MeSH
- design vybavení MeSH
- lidé MeSH
- mapování interakce mezi proteiny přístrojové vybavení metody MeSH
- mikroskopie přístrojové vybavení metody MeSH
- nukleové kyseliny analýza MeSH
- povrchová plasmonová rezonance přístrojové vybavení metody MeSH
- proteiny analýza MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
In this work, we present a study on reusable thin metal film resistivity-based sensor for direct measurement of binding of thiol containing molecules in liquid samples. While in bulk conductors the DC current is not influenced by the surface events to a measureable degree in a thin metal layer the electrons close to the surface conduct a significant part of electricity and are influenced by the surface interactions. In this study, the thickness of the gold layer was kept below 100 nm resulting in easily measureable resistivity changes of the metal element upon a surface SH-groups binding. No further surface modifications were necessary. Thin film gold layers deposited on a glass substrate by vacuum sputtering were photolithographically structured into four sensing elements arranged in a Wheatstone bridge to compensate for resistance fluctuations due to the temperature changes. Concentrations as low 100 pM provided measureable signals. The surface after the measurement could be electrolytically regenerated for next measurements.
A plasmonic biosensor for rapid detection of protein biomarkers in complex media is reported. Clinical serum samples were analyzed by using a novel biointerface architecture based on poly[(N-(2-hydroxypropyl) methacrylamide)-co-(carboxybetaine methacrylamide)] brushes functionalized with bioreceptors. This biointerface provided an excellent resistance to fouling even after the functionalization and allowed for the first time the direct detection of antibodies against hepatitis B surface antigen (anti-HBs) in clinical serum samples using surface plasmon resonance (SPR). The fabricated SPR biosensor allowed discrimination of anti-HBs positive and negative clinical samples in 10min. Results are validated by enzyme-linked immunoassays of the sera in a certified laboratory. The sensor could be regenerated by simple treatment with glycine buffer.
- MeSH
- akrylamidy chemie MeSH
- design vybavení MeSH
- hepatitida B - antigeny povrchové imunologie MeSH
- hepatitida B krev imunologie MeSH
- lidé MeSH
- limita detekce MeSH
- povrchová plasmonová rezonance přístrojové vybavení MeSH
- povrchové vlastnosti MeSH
- protilátky virové krev imunologie MeSH
- virus hepatitidy B imunologie izolace a purifikace MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- validační studie MeSH
We report an ultra-low fouling surface plasmon resonance imaging (SPRi) biosensor for the rapid simultaneous detection of multiple miRNAs in erythrocyte lysate (EL) at subpicomolar levels without need of RNA extraction. The SPRi chips were coated with ultra-low fouling functionalizable poly(carboxybetaine acrylamide) (pCBAA) brushes having optimized thicknesses and directly functionalized with amino-modified oligonucleotide probes. We have characterized the effect of the brush thickness on the probe loading capacity: a loading capacity of ~9.8×10(12) probes/cm(2) was achieved for pCBAA having a thickness of ~40 nm. The probe-functionalized sensor also exhibited a high resistance to fouling from ~90% EL samples (<2 ng/cm(2)). A two-step detection assay was employed for multiplexed miRNA detection in EL. Specifically, the assay consisted of (i) a sandwich-type hybridization of the probe-functionalized pCBAA with target miRNA in EL (bound to biotinylated oligonucleotides) and (ii) the capture of streptavidin-functionalized gold nanoparticles to the aforementioned biotinylated probes. We have demonstrated that this approach enables the detection of miRNAs in EL at concentrations as low as 0.5 pM. Finally, we have confirmed the detection of four endogenous miRNAs representing a set of potential miRNA biomarkers of myelodysplastic syndrome (MDS) in clinical EL samples (miR-16, miR-181, miR-34a, and miR-125b). The results revealed significantly higher levels of miR-16 in all the clinical EL samples compared to the other measured miRNAs.
- MeSH
- akrylamidy chemie MeSH
- analýza selhání vybavení MeSH
- biokompatibilní potahované materiály chemická syntéza MeSH
- biosenzitivní techniky přístrojové vybavení MeSH
- design vybavení MeSH
- frakcionace buněk MeSH
- komplexní směsi analýza MeSH
- mikro RNA analýza chemie genetika MeSH
- polymery chemie MeSH
- povrchová plasmonová rezonance přístrojové vybavení MeSH
- reprodukovatelnost výsledků MeSH
- senzitivita a specificita MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The process of DNA transposition involves the binding, cleavage, and recombination of specific DNA segments (transposable elements, TE) and is catalyzed by special enzymes encoded by the TE transposases. REP-associated tyrosine transposases (RAYTs) are a class of Y1 nucleases related to the IS200/IS605 transposases associated with a bacterial TE known as repetitive extragenic palindrome elements (REPs). Although RAYT has been subject of numerous studies, where DNA binding and cleavage by RAYT have been confirmed for Escherichia coli, the molecular mechanism of DNA insertion has not been fully understood. In this work, it is demonstrated that surface plasmon resonance (SPR) biosensor technology combined with a system of DNA hairpin probes (mimicking the natural REP sequence) and short oligonucleotides (ONs) can provide a rapid and real-time platform for monitoring and quantification of RAYT activity. We utilized RAYT from E. coli (strain MG1655) as a model system, where we evaluated its activity towards both a natural REP sequence as well as REP sequences having modifications targeting specific features of the DNA crucial for the DNA binding and cleavage. The characteristics of the RAYT-DNA interaction obtained by means of the SPR approach were compared with the results of SDS-PAGE analysis.
- MeSH
- biosenzitivní techniky přístrojové vybavení metody MeSH
- Escherichia coli enzymologie MeSH
- povrchová plasmonová rezonance přístrojové vybavení metody MeSH
- proteiny z Escherichia coli chemie genetika metabolismus MeSH
- regulace genové exprese enzymů fyziologie MeSH
- regulace genové exprese u bakterií fyziologie MeSH
- transposasy chemie genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Glycan biochips and biosensors are potentially important tools for detection of glycan – protein interactions. Among several applications they can be used for rapid and precise diagnosis of various diseases and infections. Two major detection techniques available for construction of glycan biochips and biosensors – fluorescent labelled and label-free methods are discussed.
- MeSH
- bakteriální infekce * diagnóza MeSH
- biosenzitivní techniky * metody přístrojové vybavení využití MeSH
- chemické techniky analytické MeSH
- diagnostické zobrazování metody využití MeSH
- DNA sondy * MeSH
- fluoroimunoanalýza metody využití MeSH
- lidé MeSH
- optické zobrazování metody využití MeSH
- polysacharidy analýza chemie MeSH
- povrchová plasmonová rezonance metody přístrojové vybavení využití MeSH
- proteiny chemie MeSH
- spektrální analýza metody využití MeSH
- virové nemoci * diagnóza MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
Surface plasmon resonance sensors have made vast advancements in the sensing technology and the number of applications achievable. New developments in surface plasmon resonance sensors have gained considerable momentum promoted by the urgent needs of fast, reliable and label-free methods for detection and quantification of analytes in molecular biology, medicine and other life sciences. However, even if enormous improvements in the limits of detections have been achieved, this technology still faces important challenges to be translated to clinical practice or in-field measurements. This paper reviews the important recent advances of this technology for the label-free detection in real biological samples and we discussed the key challenges to be overcome to transit from prototypes to commercial biosensors.
- MeSH
- biologie přístrojové vybavení metody MeSH
- diagnóza MeSH
- lidé MeSH
- povrchová plasmonová rezonance přístrojové vybavení metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Label-free affinity biosensors offer a promising platform for the development of a new generation of medical diagnostic technologies. Nevertheless, when such sensors are used in complex biological media, adsorption of non-targeted medium components prevents the specific detection of the analyte. In this work, we introduce for the first time a biosensor assay based on surface plasmon resonance (SPR) capable of diagnosing different stages of Epstein-Barr virus (EBV) infections in clinical serum samples. This was achieved by simultaneous detection of the antibodies against three different antigens present in the virus. To prevent the interference of the fouling from serum during the measurement, the SPR chips were coated by an antifouling layer of a polymer brush of poly[oligo(ethylene glycol) methacrylate] grown by surface-initiated atom transfer radical polymerization. The bioreceptors were then attached via hybridization of complementary oligonucleotides. This allowed the sensor surface to be regenerated after measurement by disrupting the complementary pairs above the oligonucleotides' melting temperature and attaching new bioreceptors. In this way, the same sensing surface could be used repeatedly. The procedure used in this work will serve as a prototype strategy for the development of label-free affinity biosensors for diagnostics in blood serum or plasma samples. This is the first example of detection of marker of a disease in clinical serum samples by an optical affinity biosensor.
- MeSH
- analýza selhání vybavení MeSH
- biosenzitivní techniky přístrojové vybavení MeSH
- design vybavení MeSH
- imunoanalýza přístrojové vybavení MeSH
- infekce virem Epsteina-Barrové krev diagnóza imunologie MeSH
- lidé MeSH
- povrchová plasmonová rezonance přístrojové vybavení MeSH
- protilátky virové imunologie MeSH
- reprodukovatelnost výsledků MeSH
- senzitivita a specificita MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Affinity-based biosensing systems have become an important analytical tool for the detection and study of numerous biomolecules. The merging of these sensing technologies with microfluidic flow cells allows for faster detection times, increased sensitivities, and lower required sample volumes. In order to obtain a higher degree of performance from the sensor, it is important to know the effects of the flow cell geometry on the sensor sensitivity. In these sensors, the sensor sensitivity is related to the overall diffusive flux of analyte to the sensing surface; therefore increases in the analyte flux will be manifested as an increase in sensitivity, resulting in a lower limit of detection (LOD). Here we present a study pertaining to the effects of the flow cell height H on the analyte flux J, where for a common biosensor design we predict that the analyte flux will scale as J ≈ H(-2/3). We verify this scaling behavior via both numerical simulations as well as an experimental surface plasmon resonance (SPR) biosensor. We show the reduction of the flow cell height can have drastic effects on the sensor performance, where the LOD of our experimental system concerning the detection of ssDNA decreases by a factor of 4 when H is reduced from 47 μm to 7 μm. We utilize these results to discuss the applicability of this scaling behavior with respect to a generalized affinity-based biosensor.
