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Communications Biology Oct 2022The analysis of trace amounts of proteins based on immunoassays and other methods is essential for the early diagnosis of various diseases such as cancer, dementia, and...
The analysis of trace amounts of proteins based on immunoassays and other methods is essential for the early diagnosis of various diseases such as cancer, dementia, and microbial infections. Here, we propose a light-induced acceleration of antigen-antibody reaction of attogram-level proteins at the solid-liquid interface by tuning the laser irradiation area comparable to the microscale confinement geometry for enhancing the collisional probability of target molecules and probe particles with optical force and fluidic pressure. This principle was applied to achieve a 10-fold higher sensitivity and ultrafast specific detection in comparison with conventional protein detection methods (a few hours) by omitting any pretreatment procedures; 47-750 ag of target proteins were detected in 300 nL of sample after 3 minutes of laser irradiation. Our findings can promote the development of proteomics and innovative platforms for high-throughput bio-analyses under the control of a variety of biochemical reactions.
Topics: Antigen-Antibody Reactions; Early Detection of Cancer; Immunoassay; Proteins
PubMed: 36203087
DOI: 10.1038/s42003-022-03946-0 -
Critical Reviews in Analytical Chemistry Oct 2022Mass spectrometry (MS) is a formidable analytical tool for the analysis of non-polar to polar compounds individually and/or from mixtures, providing information on the... (Review)
Review
Mass spectrometry (MS) is a formidable analytical tool for the analysis of non-polar to polar compounds individually and/or from mixtures, providing information on the molecular weights and chemical structures of the analytes. During the last more than one-decade, ambient ionization mass spectrometry (AIMS) has developed quickly, producing a wide range of platforms and proving scientific improvements in a variety of domains, from biological imaging to quick quality control. These methods have made it possible to detect target analytes in real time without sample preparation in an open environment, and they can be connected to any MS system with an atmospheric pressure interface. They also have the ability to analyze explosives, illicit drugs, disease diagnostics, drugs in biological samples, adulterants in food and agricultural products, reaction progress, and environmental monitoring. The development of novel ambient ionization techniques, such as probe electrospray ionization, paper spray ionization, and fiber spray ionization, employed even at picolitre to femtolitre solution levels to provide femtogram to attogram levels of the target analytes. The special characteristic of this ambient ion source, which has been extensively used, is the noninvasive property of PESI of examination of biological real samples. The results in the current review supports the idea that AIMS has emerged as a pioneer in MS-based approaches and that methods will continue to be developed along with improvements to existing ones in the near future.
PubMed: 36206159
DOI: 10.1080/10408347.2022.2124840 -
Metallomics : Integrated Biometal... Dec 2022X-ray fluorescence microscopy (XFM) has become a widely used technique for imaging the concentration and distribution of metal ions in cells and tissues. Recent advances... (Review)
Review
X-ray fluorescence microscopy (XFM) has become a widely used technique for imaging the concentration and distribution of metal ions in cells and tissues. Recent advances in synchrotron sources, optics, and detectors have improved the spatial resolution of the technique to <10 nm with attogram detection sensitivity. However, to make XFM most beneficial for bioimaging-especially at the nanoscale-the metal ion distribution must be visualized within the subcellular context of the cell. Over the years, a number of approaches have been taken to develop X-ray-sensitive tags that permit the visualization of specific organelles or proteins using XFM. In this review, we examine the types of X-ray fluorophore used, including nanomaterials and metal ions, and the approaches used to incorporate the metal into their target binding site via antibodies, genetically encoded metal-binding peptides, affinity labeling, or cell-specific peptides. We evaluate their advantages and disadvantages, review the scientific findings, and discuss the needs for future development.
Topics: X-Rays; Metals; Proteins; Ions; Microscopy, Fluorescence
PubMed: 36537552
DOI: 10.1093/mtomcs/mfac093 -
Polymers Dec 2023Microplastic pollution is a growing public concern as these particles are ubiquitous in various environments and can fragment into smaller nanoplastics. Another...
Microplastic pollution is a growing public concern as these particles are ubiquitous in various environments and can fragment into smaller nanoplastics. Another environmental concern arises from widely used engineered nanoparticles. Despite the increasing abundance of these nano-sized pollutants and the possibility of interactions with organisms at the sub cellular level, with many risks still being unknown, there are only a few publications on this topic due to the lack of reliable techniques for nanoparticle characterization. We propose a multi-technique approach for the characterization of nanoparticles down to the 10 nm level using standard micro-Raman spectroscopy combined with standard atomic force microscopy. We successfully obtained single-particle spectra from 25 nm sized polystyrene and 9 nm sized TiO nanoparticles with corresponding mass limits of detection of 8.6 ag (attogram) and 1.6 ag, respectively, thus demonstrating the possibility of achieving an unambiguous Raman signal from a single, small nanoparticle with a resolution comparable to more complex and time-consuming technologies such as Tip-Enhanced Raman Spectroscopy and Photo-Induced Force Microscopy.
PubMed: 38139897
DOI: 10.3390/polym15244644 -
ACS Applied Materials & Interfaces Apr 2022Ultrahigh sensitivity and selectivity are the ultimate goals of sensor development. For such purposes, we propose a sensing platform in which an optical...
Ultrahigh sensitivity and selectivity are the ultimate goals of sensor development. For such purposes, we propose a sensing platform in which an optical fiber-waveguide-fiber (OFWF) structure is integrated with a molecularly imprinted polymer (MIP). The OFWF works as a highly efficient probe light launcher and signal light collector, and the MIP layer acts as a highly selective and sensitive sensing interface. In the MIP design, a high-molecular refractive index monomer (2-phenylphenoxyethyl acrylate) was copolymerized with a MIP functional monomer (acrylic acid). The resulting high-refractive index MIP layers could effectively extract the probe light from the waveguide and send it to the MIP sensing interface. Moreover, a highly elastic cross-linker (poly(ethylene glycol) 600 diacrylate) was employed to increase the MIP mesh size, which could effectively increase the penetrability of the analyte. Rhodamine B (Rh B) is widely used in the textile industry, and its contamination may lead to serious public health problems. As a proof of concept, the Rh B chromophore was used as a molecular template, and the thin MIP layer was cured on the waveguide surface by utilizing the evanescent wave of the 405 nm propagating light in the waveguide. The MIP-OFWF sensing platform afforded highly selective monitoring of the absorption spectra of the components in a mixture solution of Rh B and methyl blue. It also afforded an extremely low detection limit of approximately 6.5 × 10 g/mL, with an absolute mass of 20-30 ag.
PubMed: 35363485
DOI: 10.1021/acsami.2c02362 -
Frontiers in Immunology 2021Engineered gold nanoparticles (AuNPs) find application in several fields related to human activities (, food and cosmetic industry or water purification) including...
Engineered gold nanoparticles (AuNPs) find application in several fields related to human activities (, food and cosmetic industry or water purification) including medicine, where they are employed for diagnosis, drug delivery and cancer therapy. As for any material/reagent for human use, the safety of AuNPs needs accurate evaluation. AuNPs are prone to contamination by bacterial endotoxin (lipopolysaccharide, LPS), a potent elicitor of inflammatory responses in mammals. It is therefore important, when assessing AuNP immunosafety and immune-related effects, to discriminate between inflammatory effects intrinsic to the NPs from those caused by an undeliberate and undetected LPS contamination. Detection of LPS contamination in AuNP preparations poses different problems when using the current LPS detection assays, given the general interference of NPs, similar to other particulate agents, with the assay reagents and endpoints. This leads to time-consuming search for optimal assay conditions for every NP batch, with unpredictable results, and to the use in parallel of different assays, each with its weaknesses and unpredictability. Thus, the development of highly sensitive, quantitative and accurate assays able to detect of LPS on AuNPs is very important, in view of their medical applications. Surface-enhanced Raman spectroscopy (SERS) is a label-free, sensitive, chemical-specific, nondestructive and fast technique that can be used to directly obtain molecular fingerprint information and a quantitative analysis of LPS adsorbed on AuNPs. Within this study, we describe the use of SERS for the label-free identification and quantitative evaluation - down to few attograms - of the LPS adsorbed on the surface of 50 nm AuNPs. We thus propose SERS as an efficient tool to detect LPS on the AuNP surface, and as the basis for the development of a new sensitive and specific LPS-detection sensor based on the use of AuNPs and SERS.
Topics: Biosensing Techniques; Gold; Humans; Lipopolysaccharides; Metal Nanoparticles; Spectrum Analysis, Raman; Surface Properties
PubMed: 34691081
DOI: 10.3389/fimmu.2021.758410 -
Journal of Helminthology Nov 2023Molecular techniques are an alternative for the diagnosis of strongyloidiasis, produced by However, it is necessary to determine the best amplification target for the...
Molecular techniques are an alternative for the diagnosis of strongyloidiasis, produced by However, it is necessary to determine the best amplification target for the populations of this parasite present in a geographical area and standardize a polymerase chain reaction (PCR) protocol for its detection. The objectives of this work were the comparison of different PCR targets for molecular detection of and the standardization of a PCR protocol for the selected target with the best diagnostic results. DNA extraction was performed from parasite larvae by saline precipitation. Three amplification targets of the genes encoding ribosomal RNA 18S (18S rDNA) and 5.8S (5.8S rDNA) and cytochrome oxidase 1 (COX1) of were compared, and the PCR reaction conditions for the best target were standardized (concentration of reagents and template DNA, hybridization temperature, and number of cycles). The analytical sensitivity and specificity of the technique were determined. DNA extraction by saline precipitation made it possible to obtain DNA of high purity and integrity. The ideal target was the 5.8S rDNA, since the 18S rDNA yielded non-reproducible results and COX1 never amplified under any condition tested. The optimal conditions for the 5.8S rDNA-PCR were: 1.5 mM MgCl, 100 μM dNTPs, 0.4 μM primers, and 0.75 U DNA polymerase, using 35 cycles and a hybridization temperature of 60 °C. The analytical sensitivity of the PCR was 1 attogram of DNA, and the specificity was 100%. Consequently, the 5.8S rDNA was shown to be highly sensitive and specific for the detection of DNA.
Topics: Animals; Strongyloides stercoralis; Strongyloidiasis; Polymerase Chain Reaction; RNA, Ribosomal, 18S; DNA, Ribosomal; Feces
PubMed: 37974436
DOI: 10.1017/S0022149X23000743 -
Nature Communications Mar 2021Optical evanescent sensors can non-invasively detect unlabeled nanoscale objects in real time with unprecedented sensitivity, enabling a variety of advances in...
Optical evanescent sensors can non-invasively detect unlabeled nanoscale objects in real time with unprecedented sensitivity, enabling a variety of advances in fundamental physics and biological applications. However, the intrinsic low-frequency noise therein with an approximately 1/f-shaped spectral density imposes an ultimate detection limit for monitoring many paramount processes, such as antigen-antibody reactions, cell motions and DNA hybridizations. Here, we propose and demonstrate a 1/f-noise-free optical sensor through an up-converted detection system. Experimentally, in a CMOS-compatible heterodyne interferometer, the sampling noise amplitude is suppressed by two orders of magnitude. It pushes the label-free single-nanoparticle detection limit down to the attogram level without exploiting cavity resonances, plasmonic effects, or surface charges on the analytes. Single polystyrene nanobeads and HIV-1 virus-like particles are detected as a proof-of-concept demonstration for airborne biosensing. Based on integrated waveguide arrays, our devices hold great potentials for multiplexed and rapid sensing of diverse viruses or molecules.
Topics: Biosensing Techniques; HEK293 Cells; Humans; Interferometry; Limit of Detection; Nanoparticles; Nanotechnology; Signal Processing, Computer-Assisted
PubMed: 33785760
DOI: 10.1038/s41467-021-22271-4 -
Analytical Chemistry Feb 2023Accelerator mass spectrometry (AMS) is one of the most sensitive techniques used to measure the long-lived actinides. This is particularly of interest for determination...
Accelerator mass spectrometry (AMS) is one of the most sensitive techniques used to measure the long-lived actinides. This is particularly of interest for determination of ultra-trace transuranium nuclides and their isotopic fingerprints for nuclear forensics. In this work, a new method was developed for simultaneous determination of transuranium nuclides (Np, Pu, Am, and Cm isotopes) by using 300 kV AMS after a sequential chemical separation of each group of actinides. Pu and Am were utilized as tracers for Np/Pu and Am/Cm yield monitoring. The results show that the chemical behaviors of Np and Pu on the TK200 column and those of Am and Cm on the DGA column were very consistent in 8-9 mol/L of HNO and 0.015-0.03 mol/L of NaNO media during the radiochemical separation. The AMS detection efficiencies for transuranium nuclides were also evaluated. The detection limits for all radionuclides are below femtogram level and even in attogram level for Pu and Cm isotopes. The established method has been successfully applied to accurately measure various transuranium nuclides in a single actinide radionuclide solution, demonstrating its feasibility for nuclear forensic investigation.
PubMed: 36763009
DOI: 10.1021/acs.analchem.2c04544 -
Investigative Radiology May 2024Gadolinium-based contrast agents (GBCAs) are routinely used in magnetic resonance imaging (MRI) examinations. However, there is limited knowledge about the interaction...
OBJECTIVES
Gadolinium-based contrast agents (GBCAs) are routinely used in magnetic resonance imaging (MRI) examinations. However, there is limited knowledge about the interaction with and distribution of the drug in human cells. This lack of knowledge is surprising, given that the first interaction of the drug occurs with blood cells. Moreover, recent studies reported gadolinium (Gd) deposition within organs, such as the brain. Hence, this study is aiming to determine the uptake of GBCA in blood cells of patients undergoing contrast-enhanced MRI (ce-MRI) examination.
MATERIALS AND METHODS
Human blood was exposed to either gadoterate meglumine (Gd-DOTA) or Eu-DOTA in vitro or was collected from patients undergoing ce-MRI with Gd-DOTA. Uptake of contrast agents (CAs) by blood cells was quantified by Gd measurements using single-cell inductively coupled plasma mass spectrometry (SC-ICP-MS) or, to confirm Gd-DOTA uptake, by a complementary method using Eu-DOTA by time-resolved fluorescence spectroscopy, respectively.
RESULTS
Uptake of Gd-DOTA or Eu-DOTA into white blood cells (WBCs) ex vivo was detectable by SC-ICP-MS and time-resolved fluorescence spectroscopy. The intracellular concentrations were estimated to be in the range of 1-3 μM. However, no CA uptake into erythrocytes was detected with either method. In total, 42 patients between 30 and 84 years old (24 men, 18 women) were enrolled. White blood cells' uptake of Gd was measured by SC-ICP-MS. Isolated WBCs from patients who underwent ce-MRI examination showed substantial Gd uptake; however, the studied patient group showed an inhomogeneous distribution of Gd uptake. Measurements immediately after MRI examination indicated 21-444 attogram/WBC, corresponding to an intracellular Gd concentration in the range from 0.2 to 5.5 μM.
CONCLUSIONS
This study confirms the ex vivo uptake of GBCA by WBCs and provides the first evidence that GBCA is indeed taken up by WBCs in vivo by patients undergoing ce-MRI examination. However, the observed Gd uptake in WBCs does not follow a log-normal distribution commonly observed in the fields of environmental studies, biology, and medicine. Whether cellular uptake of GBCA is linked to the observed deposition of Gd remains unclear. Therefore, studying the interaction between GBCA and human cells may clarify crucial questions about the effects of Gd on patients after MRI examinations.
Topics: Male; Animals; Humans; Female; Adult; Middle Aged; Aged; Aged, 80 and over; Contrast Media; Gadolinium; Gadolinium DTPA; Models, Animal; Organometallic Compounds; Erythrocytes; Brain; Magnetic Resonance Imaging; Heterocyclic Compounds
PubMed: 37824716
DOI: 10.1097/RLI.0000000000001029