High sensitivity detection of NBT on novel SERS substrate

Surface-enhanced Raman scattering (SERS) is rapidly evolving as a useful analytical tool in chemical and biological analysis. The most critical aspect of SERS is the research of efficient SERSactive substrates, such as nanostructured surface or nanoparticles of noble metals with suitable physical parameters such as their material, size, shape, and spacing [1]. Generally, Ag and Au substrates are regarded as one of the best candidates for SERS. Nevertheless, fabrication of SERS substrates with both high sensitivity and high reproducibility remains difficult, and it is costly for routine SERS detection. We report the novel combined substrate for highly sensitive Surface Enhanced Raman spectroscopy (SERS) are capable of detecting 4-nitrobenzenethiol (NBT), as a model Raman active molecule, at very low concentration

High sensitivity detection of NBT on novel SERS substrate

Surface-enhanced Raman scattering (SERS) is rapidly evolving as a useful analytical tool in chemical and biological analysis. The most critical aspect of SERS is the research of efficient SERSactive substrates, such as nanostructured surface or nanoparticles of noble metals with suitable physical parameters such as their material, size, shape, and spacing [1]. Generally, Ag and Au substrates are regarded as one of the best candidates for SERS. Nevertheless, fabrication of SERS substrates with both high sensitivity and high reproducibility remains difficult, and it is costly for routine SERS detection. We report the novel combined substrate for highly sensitive Surface Enhanced Raman spectroscopy (SERS) are capable of detecting 4-nitrobenzenethiol (NBT), as a model Raman active molecule, at very low concentration

Subnanomolar detection of tuberculosis biomarker MPT64 in sandwich sers immunoassay on novel low -cost substrate

The use of SERS for detection, analysis and imaging has attracted great interest in the past decade owing to its high sensitivity and molecular fingerprint specificity. There is an increasing interest in scientific community to SERS as it becomes a versatile method for early medical diagnostics and reliable detection of major health threats to humans (e.g. cancer, tuberculosis, etc) and animals [1]. The key component of our SERS-based immunoassay include:1) a capture substrate to specifically adsorb antigens from solution; (2) Extrinsic Raman Labels (ERLs): surface functionalized gold nanoparticles (AuNPs) to bind to captured antigens selectively and generate intense SERS signals, which contain both capture antigen and SERS active readout molecule (4-nitrobenzenethiol (4-NBT))

Subnanomolar detection of tuberculosis biomarker MPT64 in sandwich sers immunoassay on novel low -cost substrate

The use of SERS for detection, analysis and imaging has attracted great interest in the past decade owing to its high sensitivity and molecular fingerprint specificity. There is an increasing interest in scientific community to SERS as it becomes a versatile method for early medical diagnostics and reliable detection of major health threats to humans (e.g. cancer, tuberculosis, etc) and animals [1]. The key component of our SERS-based immunoassay include:1) a capture substrate to specifically adsorb antigens from solution; (2) Extrinsic Raman Labels (ERLs): surface functionalized gold nanoparticles (AuNPs) to bind to captured antigens selectively and generate intense SERS signals, which contain both capture antigen and SERS active readout molecule (4-nitrobenzenethiol (4-NBT))

Quantifying impact of the low-cost SERS substrate on SERS signal

Surface-Enhanced Raman Spectroscopy (SERS) allows structural detection of molecules absorbed on rough noble metal surfaces by amplifying a normally weak Raman signal. It can be applied in forensic science, biosensing, food safety, and medical diagnostics [1]. Although costly gold and silver films are used as SERS substrates, AuNPs (gold nanoparticles) on aluminum foil can become a low-cost alternative

Quantifying impact of the low-cost SERS substrate on SERS signal

Surface-Enhanced Raman Spectroscopy (SERS) allows structural detection of molecules absorbed on rough noble metal surfaces by amplifying a normally weak Raman signal. It can be applied in forensic science, biosensing, food safety, and medical diagnostics [1]. Although costly gold and silver films are used as SERS substrates, AuNPs (gold nanoparticles) on aluminum foil can become a low-cost alternative

Commercial Gold Nanoparticles on Untreated Aluminum Foil: Versatile, Sensitive, and Cost-Effective SERS Substrate

We introduce low-cost, tunable, hybrid SERS substrate of commercial gold nanoparticles on untreated aluminum foil (AuNPs@AlF). Two or three AuNP centrifugation/resuspension cycles are proven to be critical in the assay preparation.The limits of detection (LODs) for 4-nitrobenzenethiol (NBT) and crystal violet (CV) on this substrate are about 0.12nM and 0.19 nM, respectively, while maximum analytical SERS enhancement factors (AEFs) are about 107. In comparative assays LODs for CV measured on AuNPs@Au film and AuNPs@glass are about 0.35 nM and 2 nM, respectively. The LOD for melamine detected on AuNPs@ Al foil is 27 ppb with 3 orders of magnitude for linear response range. Overall, AuNPs@AlF demonstrated competitive performance in comparison with AuNPs@Au film substrate in SERS detection of CV, NBT, andmelamine. To check the versatility of the AuNPs@AlF substrate we also detectedKNO3 with LODs of 0.7mMand SERS EF around 2 × 103, which is on the same order with SERS EF reported for this compound in the literature

Models and methods of resource management for VPS hosting

The paper summarizes models and methods of data center resource management for VPS hosting. The approach for the allocation of computing resources in the form of particles of a predetermined size (virtual nodes) was proposed. Different cases of this problem for both an excess and a lack of computing resources were considered. These problems belong to the classes of linear and nonlinear Boolean programming. To solve the mentioned problems, heuristic and guided genetic algorithms have been proposed. A comparison of their effectiveness was carried out

SURFACE-ENHANCED RAMAN SPECTROSCOPY (SERS) FOR PROTEIN DETERMINATION IN HUMAN URINE

Excessive protein excretion in human urine is an early and sensitive marker of diabetic nephropathy, primary and secondary renal disease. Kidney problems, particularly chronic kidney disease, remain among the few growing causes of mortality in the world. Therefore, it is important to develop efficient, expressive, and low-cost method for protein determination. Surface-enhanced Raman spectroscopy (SERS) methods are potential candidates to achieve those criteria. In this paper, the SERS method was developed to distinguish patients with proteinuria and the healthy group. Two types of commercial gold nanoparticles with a diameter of 60 nm and 100 nm were employed to prepare substrates for the analysis of 78 samples of unique patients. Data analysis by the PCA-LDA algorithm, and the ROC curves, gave results for diagnostic figures of merits. Sensitivity, specificity, accuracy, and AUC were 0.79, 0.89, 0.85, and 0.90 for the set with 60 nm Au NPs, respectively. Sensitivity, specificity, accuracy, and AUC were 0.79, 0.98, 0.90, and 0.91 for the set with 100 nm Au NPs, respectively. The results show the potential of SERS spectroscopy in differentiating between patients with proteinuria and healthy individuals for clinical diagnostics

Urinary Protein Profiling for Potential Biomarkers of Chronic Kidney Disease : A Pilot Study

Proteinuria is a risk factor for chronic kidney disease (CKD) progression and associated complications. However, there is insufficient information on individual protein components in urine and the severity of CKD. We aimed to investigate urinary proteomics and its association with proteinuria and kidney function in early-stage CKD and in healthy individuals. A 24 h urine sample of 42 individuals (21-CKD and 21-healthy individuals) was used for mass spectrometry-based proteomics analysis. An exponentially modified protein abundance index (emPAI) was calculated for each protein. Data were analyzed by Mascot software using the SwissProt database and bioinformatics tools. Overall, 298 unique proteins were identified in the cohort; of them, 250 proteins belong to the control group with median (IQR) emPAI 39.1 (19-53) and 142 proteins belong to the CKD group with median (IQR) emPAI 67.8 (49-117). The level of 24 h proteinuria positively correlated with emPAI (r = 0.390, p = 0.011). The emPAI of some urinary proteomics had close positive (ALBU, ZA2G, IGKC) and negative (OSTP, CD59, UROM, KNG1, RNAS1, CD44, AMBP) correlations (r < 0.419, p < 0.001) with 24 h proteinuria levels. Additionally, a few proteins (VTDB, AACT, A1AG2, VTNC, and CD44) significantly correlated with kidney function. In this proteomics study, several urinary proteins correlated with proteinuria and kidney function. Pathway analysis identified subpathways potentially related to early proteinuric CKD, allowing the design of prospective studies that explore their response to therapy and their relationship to long-term outcome