Detection of microRNA-335-5p on an Interdigitated Electrode Surface for Determination of the Severity of Abdominal Aortic Aneurysms

Gold nanourchin on multiple-point dielectrode for glucose biosensing by current-potential measurement

Gestational diabetes (GD) is a condition characterized by elevated blood sugar levels during pregnancy. GD poses various health risks, such as serious birth injuries, the need for cesarean delivery, and the necessity of newborn care. Monitoring glucose levels is essential for ensuring safe delivery and reducing the risks to both the mother and fetus. Various sensors are readily available for monitoring glucose levels, and researchers are continually working to develop highly sensitive glucose sensors. This research aimed to develop a gold nanourchin (AuNU)-hybrid biosensor for quantifying glucose on a multi-point electrode sensor. Glucose oxidase (GOx) was attached to the AuNU and seeded on the sensing surface using an amine linker. The current-potential (1-2 V at 0.1 V sweep) was recorded for the GOx-glucose interaction, with a limit of detection of 560 μM and a regression coefficient (R2) of 0.9743 [y = 0.9106x - 0.9953] on the linear curve. The sensitivity was estimated to be 3.5 mAcm-2M-1. Furthermore, control experiments with galactose, sucrose, and fructose did not yield an increase in current-potential, confirming specific glucose detection. This experiment helps in monitoring glucose levels to manage conditions associated with GD.

A Miniature Biomedical Sensor for Rapid Detection of Schistosoma japonicum Antibodies

Schistosomiasis, typically characterized by chronic infection in endemic regions, has the potential to affect liver tissue and pose a serious threat to human health. Detecting and screening for this disease early on is crucial for its prevention and control. However, existing methods encounter challenges such as low sensitivity, time-consuming processes, and complex sample handling. To address these challenges, we report a soluble egg antigen (SEA)-based functionalized gridless and meander-type AlGaN/GaN high electron mobility transistors (HEMT) sensor for the highly sensitive detection of antibodies to Schistosoma japonicum. Immobilization of the self-assembled membrane on the gate surface was verified using a semiconductor parameter analyzer, scanning electron microscope (SEM), and atomic force microscopy (AFM). The developed biosensor demonstrates remarkable performance in detecting anti-SEA, exhibiting a linear concentration range of 10 ng/mL to 100 μg/mL and a sensitivity of 0.058 mA/log (ng/mL). It also exhibits similar excellent performance in serum systems. With advantages such as rapid detection, high sensitivity, miniaturization, and label-free operation, this biosensor can fulfill the requirements for blood defense.

Non-protein coding RNA sequences mediate specific colorimetric detection of Staphylococcus aureus on unmodified gold nanoparticles

Nonprotein coding RNA (npcRNA) is a transcribed gene sequence that is not able to translate into protein, yet it executes a specific function in modulation and regulation mechanisms. As npcRNA is highly resistant to the mutation, the Sau-02 npcRNA gene and its probe oligonucleotide, which are specifically present in Staphylococcus aureus and in methicillin-resistant S. aureus only, used to develop a highly specific and sensitive colorimetric assay on unmodified gold nanoparticles (AuNPs). Hybridization between the npcRNA Sau-02 gene sequences was detected through noncrosslinking AuNP aggregation in salt solution in the presence of probe-target gene sequences. AuNPs of 10 and 15 nm in sizes with monovalent ion salt (NaCl) solution were optimized as the ideal tool for investigating the stability of AuNPs upon the addition of gene sequences. The state dispersed and aggregated forms of 10 nm AuNPs with the presented colorimetric assay were justified through field emission scanning electron microscopy and atomic force microscopy. The particle distribution of two different AuNP states was evaluated through particle distribution analysis. The lowest detection amount of S. aureus npcRNA from the colorimetric assay performed was 6 pg/µL, as the color of AuNPs turned blue with the presence of probe oligonucleotides and target gene sequences.

Gold nanourchin enhances detection of Alzheimer's disease biomarker "miRNA-137" on dual electrode sensing surface

Diagnosis of Alzheimer's disease (AD) is a complex task, and at present, neuroimaging such as magnetic resonance imaging and positron emission tomography is commonly used for the diagnosis of AD. This research work developed a new biosensing method with gold nanomaterial to identify AD biomarker of miRNA-137. Gold nanourchin (GNU) was attached on the interdigitated electrode through the silane linker and COOH-ended capture oligonucleotide was immobilized on the GNU surface. This surface helps to quantify the target sequence of miRNA-137 and the detection limit reached to 0.01 pM on the linear range of 0.01-100 pM. With 3δ calculation on the linearity, the determination coefficient was noticed as y = 1.2867x - 2.2697; R²  = 0.9059. The control performances did not show a significant response, indicating the specific identification of target.

Biosensing human blood clotting factor by dual probes: Evaluation by deep long short-term memory networks in time series forecasting

Artificial intelligence of things (AIoT) has become a potential tool for use in a wide range of fields, and its use is expanding in interdisciplinary sciences. On the other hand, in a clinical scenario, human blood-clotting disease (Royal disease) detection has been considered an urgent issue that has to be solved. This study uses AIoT with deep long short-term memory networks for biosensing application and analyzes the potent clinical target, human blood clotting factor IX, by its aptamer/antibody as the probe on the microscaled fingers and gaps of the interdigitated electrode. The earlier results by the current-volt measurements have shown the changes in the surface modification. The limit of detection (LOD) was noticed as 1 pM with the antibody as the probe, whereas the aptamer behaved better with the LOD at 100 fM. The time-series predictions from the AIoT application supported the obtained results with the laboratory analyses using both probes. This application clearly supports the results obtained from the interdigitated electrode sensor as aptamer to be the better option for analyzing the blood clotting defects. The current study supports a great implementation of AIoT in sensing application and can be followed for other clinical biomarkers.

Current-Volt Biosensing "Cystatin C" on Carbon Nanowired Interdigitated Electrode Surface: A Clinical Marker Analysis for Bulged Aorta

A carbon nanowire-modified surface with interdigitated electrode (IDE) sensing system was introduced to identify abdominal aortic aneurysm biomarker "papain," also known as cysteine protease, used as the capture probe to identify Cystatin C. Papain was immobilized through the covalent integration of amine group on papain and the carboxyl group with carbon nanowire. This papain-modified electrode surface was utilized to detect the different concentrations of Cystatin C (100 pg/mL to 3.2 ng/mL). The interaction between papain and Cystatin C was monitored using a picoammeter, and the response curves were compared. With increasing Cystatin C concentrations, the total current levels were gradually increased with a linear range from 200 pg/mL to 3.2 ng/mL, and the current differences were plotted and the detection limit of Cystatin C was calculated as 200 pg/mL. The averaging of three independent experiments (n = 3) was made with 3δ estimation, and the determination coefficient was y = 1.8477 × 0.7303 and R ² = 0.9878. Furthermore, control experiments with creatinine and gliadin failed to bind the immobilized papain, indicating the specific detection of Cystatin C.

Biomolecular assembly on interdigitated electrode nanosensor for selective detection of insulin-like growth factor-1

This research is focussed to quantify IGF1 by electroanalytical analysis on InterDigitated electrode surface and characterized by the microscopic observations. For the detection, antibody and aptamer were used to analyze the level of IGF1. The sandwich pattern (aptamer-IGF1-antibody) was designed on the chemically modified IDE surface and reached the limit of detection to 10 fM with 100 folds enhancement in the sensitivity. Different control experiments (absence of IGF1, binding with IGF2 and with non-complementary aptamer) were failed to show the current changes, discriminated the specific detection. A good detection strategy is to complement the currently following imaging systems for AAA.

Potentials of MicroRNA in Early Detection of Ovarian Cancer by Analytical Electrical Biosensors

The importance of nanotechnology in medical applications especially with biomedical sensing devices is undoubted. Several medical diagnostics have been developed by taking the advantage of nanomaterials, especially with electrical biosensors. Biosensors have been predominantly used for the quantification of different clinical biomarkers toward detection, screening, and follow-up the treatment. At present, ovarian cancer is one of the severe complications that cannot be identified until it becomes most dangerous as the advanced stage. Based on the American Cancer Society, 20% of cases involved in the detection of ovarian cancer are diagnosed at an early stage and 80% diagnosed at the later stages. The patient just has a common digestive problem and stomach ache as early symptoms and people used to ignore these symptoms. Micro ribonucleic acid (miRNA) is classified as small non-coding RNAs, their expressions change due to the association of cancer development and progression. This article reviews and discusses on the currently available strategies for the early detection of ovarian cancers using miRNA as a biomarker associated with electrical biosensors. A unique miRNA-based biomarker detections are specially highlighted with biosensor platforms to diagnose ovarian cancer.

Biosensors and biomarkers for determining gestational diabetes mellitus and jaundice in children

Gestational diabetes and jaundice are the correlated diseases predominantly found in mother and newborn child. Jaundice is a neonatal complication with an increased risk when mother has gestational diabetes. Mothers with diabetes at an early stage of gestational age are at higher risk for hyperbilirubinemia (jaundice) and hypoglycemia. So, it is mandatory to monitor the condition of diabetes and jaundice during the pregnancy period for a healthy child and safest delivery. On the other hand, nanotechnology has displayed a rapid advancement that can be implemented to overcome these issues. The development of high-performance diagnosis using appropriate biomarkers provides their efficacy in the detection gestational diabetes and jaundice. This review covers the aspects from a fast-developing field to generate nanosensors in the nanosized dimensions for the applications to overcome these complications by coupling diagnostics with biomarkers. Further, the serum-based biomarkers have been discussed for these inborn complications and also the diagnosis with the current trend.

Longitudinal Zeolite-Iron Oxide Nanocomposite Deposited Capacitance Biosensor for Interleukin-3 in Sepsis Detection

Sepsis is an extreme condition involving a physical response to severe microbial infection and causes fatal and life-threatening issues. Sepsis generates during the chemicals release with the immune system into the bloodstream for fighting against an infection, which causes the inflammation and leads to the medical emergency. A complexed longitudinal zeolite and iron oxide nanocomposite was extracted from coal mine fly ash and utilized to improve the surface characteristics of the capacitance biosensor to identify sepsis attacks. Anti-interleukin-3 (anti-IL-3) antibody was attached to the zeolite- and iron oxide-complexed capacitance electrode surface through an amine linker to interact with the sepsis biomarker IL-3. The morphological and chemical components of the nanocomplex were investigated by FESEM, FETEM, and EDX analyses. At approximately 30 nm, the longitudinal zeolite and iron oxide nanocomposite aided in attaining the limit of IL-3 detection of 3 pg/mL on the linear curve, with a regression coefficient (R2) of 0.9673 [y = 1.638x - 1.1847]. A lower detection limit was achieved in the dose-dependent range (3-100 pg/mL) due to the higher amount of antibody immobilization on the sensing surface due to the nanomaterials and the improved surface current. Furthermore, control experiments with relevant biomolecules did not show capacitance changes, and spiked IL-3 in human serum increased capacitance, indicating the specific and selective detection of IL-3. This study identifies and quantifies IL-3 via potentially useful methods and helps in diagnosing sepsis attack.

Molecularly imprinted polymer amalgamation on narrow-gapped Archimedean-spiral interdigitated electrodes: resistance to electrolyte fouling in acidic medium

A conventional photolithography technique was used to fabricate three types of Archimedean-spiral interdigitated electrodes (AIDEs) containing concentric interlocking electrodes with different electrode and gap sizes, i.e., 150 μm (D1), 100 μm (D2), and 50 μm (D3). The precision of the fabrication was validated by surface topography using scanning electron microscopy, high power microscopy, 3D-nano profilometry, and atomic force microscopy. These AIDEs were fabricated with a tolerance of ± 6 nm in dimensions. The insignificant current variation at the pico-ampere range for all bare AIDEs further proved the reproducibility of the device. The large gap sized AIDE (D1) is insensitive to acidic medium, whereas D2 and D3 are insensitive to alkali medium. D2 was the best with regard to its electrical characterization. Furthermore, uniformly synthesized molecularly imprinted polymer (MIP) nanoparticles prepared with human blood clotting factor IX and its aptamer were in the size range 140 to 160 nm, attached on the sensing surface and characterized. The average thickness of deposited MIP film was 1.7 μm. EDX data shows the prominent peaks for silicon and aluminum substrates as 61.79 and 22.52%, respectively. The MIP nanoparticles-deposited sensor surface was characterized by applying it in electrolyte solutions, and smooth curves with the current flow were observed at pH lower than 8 and discriminated against alkali media. This study provides a new MIP amalgamated AIDE with nano-gapped fingers enabling analysis of other biomaterials due to its operation in an ideal buffer range.

Bioinformatics analysis of common key genes and pathways of intracranial, abdominal, and thoracic aneurysms

Background

Aneurysm is a severe and fatal disease. This study aims to comprehensively identify the highly conservative co-expression modules and hub genes in the abdominal aortic aneurysm (AAA), thoracic aortic aneurysm (TAA) and intracranial aneurysm (ICA) and facilitate the discovery of pathogenesis for aneurysm.

Methods

GSE57691, GSE122897, and GSE5180 microarray datasets were downloaded from the Gene Expression Omnibus database. We selected highly conservative modules using weighted gene co‑expression network analysis before performing the Gene Ontology, Kyoto Encyclopedia of Genes and Genomes pathway and Reactome enrichment analysis. The protein–protein interaction (PPI) network and the miRNA-hub genes network were constructed. Furtherly, we validated the preservation of hub genes in three other datasets.

Results

Two modules with 193 genes and 159 genes were identified as well preserved in AAA, TAA, and ICA. The enrichment analysis identified that these genes were involved in several biological processes such as positive regulation of cytosolic calcium ion concentration, hemostasis, and regulation of secretion by cells. Ten highly connected PPI networks were constructed, and 55 hub genes were identified. In the miRNA-hub genes network, CCR7 was the most connected gene, followed by TNF and CXCR4. The most connected miRNAs were hsa-mir-26b-5p and hsa-mir-335-5p. The hub gene module was proved to be preserved in all three datasets.

Conclusions

Our study highlighted and validated two highly conservative co-expression modules and miRNA-hub genes network in three kinds of aneurysms, which may promote understanding of the aneurysm and provide potential therapeutic targets and biomarkers of aneurysm.

Graphene Oxide-Gold Star Construct on Triangular Electrodes for Alzheimer's Disease Identification

Nanotechnology is playing a major role in the field of medical diagnosis, in particular with the biosensor and bioimaging. It improves the performance of the desired system dramatically by displaying higher selectivity and sensitivity. Carbon nanomaterial, gold nanostructure, magnetite nanoparticle, and silica substrate are the most popular nanomaterials greatly contributed to make the affordable and effective biosensor at low-cost. This research work is introducing a new sensing strategy with graphene oxide-constructed triangular electrodes to diagnose Alzheimer's disease (AD). MicroRNA-137 (miRNA-137) was found as a suitable biomarker for AD, and the sensing method was established here to detect miRNA-137 on the complementary sequence. To enhance the immobilization of capture miRNA-137, gold nanostar (GNS) was conjugated with capture miRNA and immobilized on the GO-modified surface through an amine linker. This immobilization process enhanced the hybridization of the target and reaches the detection limit at 10 fM with the sensitivity of 1 fM on the linear curve with a regression coefficient of 0.9038. Further control sequences of miRNA-21 and single and triple base mismatched miRNA-137 did not show a significant response in current changes, indicating the specific miRNA-137 detection for diagnosing AD.

Magnetic nanoparticle-based amplification of microRNA detection in body fluids for early disease diagnosis

Circulating biomarkers such as microRNAs (miRNAs), short noncoding RNA strands, represent prognostic and diagnostic indicators for a variety of physiological disorders making their detection and quantification an attractive approach for minimally invasive early disease diagnosis. However, highly sensitive and selective detection methods are required given the generally low abundance of miRNAs in body fluids together with the presence of large amounts of other potentially interfering biomolecules. Although a variety of miRNA isolation and detection methods have been established in clinics, they usually require trained personnel and often constitute labor-, time- and cost-intensive approaches. During the last years, nanoparticle-based biosensors have received increasing attention due to their superior detection efficiency even in very low concentration regimes. This is based on their unique physicochemical properties in combination with their high surface area that allows for the immobilization of multiple recognition sites resulting in fast and effective recognition of analytes. Among various materials, magnetic nanoparticles have been identified as useful tools for the separation, concentration, and detection of miRNAs. Here, we review state-of-the-art technology with regard to magnetic particle-based miRNA detection from body fluids, critically discussing challenges and future perspective of such biosensors while comparing their handling, sensitivity as well as selectivity against the established miRNA isolation and detection methods.

Detection of interleukin-8 on microgapped dual electrodes for measuring asthma complication

Detection of asthma by a suitable biomarker is mandatory for the early identification, which helps in providing a right medication for the complete cure. Interleukins (ILs) have played a major role in asthma; in particular IL-8 is highly correlated with severe asthma. This research was focused on to detect IL-8 level by its partner antibody on a microgapped dual electrodes sensor. The sensing surface was modified into graphene oxide (GO), and an antibody was fixed by using the amine-aldehyde linker. GO enhanced the antibody immobilization and the consequence electric current flow upon interacting with IL-8. The detection limit of IL-8 was reached to 10 pg/mL in a linear range from 1 to 10,000 pg/mL with the regression of y = 0.7246x - 0.906 (R² = 0.9758); further, the sensitivity falls at 1 pg/mL. The surface does not show the antifouling effect with control antibody, and proteins, indicating the specific IL-8 detection. The detection of IL-8 helps in diagnosing and solving the related problems of asthmatic patients.

Fly Ash-Based Zeolite-Complexed Polyethylene-Glycol on an Interdigitated Electrode Surface for High-Performance Determination of Diabetes Mellitus

BACKGROUND

Diabetes is a complex metabolic disorder known to induce a high blood glucose level that fluctuates outside the normal range. Diabetes affects and damages the organs in the body and causes heart issues, blindness and kidney failure. Continuous monitoring is mandatory to keep the blood glucose level within a healthy range.

MATERIALS AND METHODS

This research was focused on diagnosing diabetes mellitus on zeolite nanoparticle-polyethylene glycol complex-immobilized interdigitated electrode sensor (IDE) surfaces. Zeolite nanoparticles were extracted from the fly ash of a thermal power plant by alkaline extraction. The surface morphology of the synthesized nanoparticles was observed by field-emission scanning electron microscopy and transmission electron microscopy, and the presence of certain elements and the particle size were determined by energy-dispersive X-ray spectroscopy and particle size analysis, respectively.

RESULTS

The crystalline PEG-zeolite nanoparticles were synthesized with a size of 40±10 nm according to high-resolution microscopy. A particle size analyzer revealed the sizes of the fly ash and PEG-zeolite particles as 60±10 µm and 50±10 nm, respectively. The IDE surface was evaluated for its ability to display antifouling properties and sense glucose levels on the abovementioned nanoparticle-modified surface. Glucose oxidase was probed on the PEG-zeolite-modified IDE surface, and glucose was detected. PEG zeolite performed well with excellent antifouling properties on the IDE sensor surface and improved the glucose detection limit to 0.03 mg/mL from 0.08 mg/mL, as determined by linear regressions [y = 5.365x - 6.803; R2 = 0.9035 (zeolite surface) and y = 5.498x + 5.914R2 = 0.9061 (PEG-zeolite surface)]. This enhancement was ~3-fold, and sensitivities were found to be 0.03 and 0.06 mg/mL glucose for the PEG-zeolite- and zeolite-modified surfaces, respectively, showing a 2-fold difference.

CONCLUSION

The excellent biocompatible surface modified by PEG zeolite exhibited high performance and is useful for medical diagnosis.

Identification of a Plasma Microrna Signature as Biomarker of Subaneurysmal Aortic Dilation in Patients with High Cardiovascular Risk

Patients with subaneurysmal aortic dilation (SAD; 25–29 mm diameter) are likely to progress to true abdominal aortic aneurysm (AAA). Despite these patients having a higher risk of all-cause mortality than subjects with aortic size <24 mm, early diagnostic biomarkers are lacking. MicroRNAs (miRs) are well-recognized potential biomarkers due to their differential expression in different tissues and their stability in blood. We have investigated whether a plasma miRs profile could identify the presence of SAD in high cardiovascular risk patients. Using qRT-PCR arrays in plasma samples, we determined miRs differentially expressed between SAD patients and patients with normal aortic diameter. We then selected 12 miRs to be investigated as biomarkers by construction of ROC curves. A total of 82 significantly differentially expressed miRs were found by qPCR array, and 12 were validated by qRT-PCR. ROC curve analyses showed that seven selected miRs (miR-28-3p, miR-29a-3p, miR-93-3p, miR-150-5p, miR-338-3p, miR-339-3p, and miR-378a-3p) could be valuable biomarkers for distinguishing SAD patients. MiR-339-3p showed the best sensitivity and specificity, even after combination with other miRs. Decreased miR-339-3p expression was associated with increased aortic abdominal diameter. MiR-339-3p, alone or in combination with other miRs, could be used for SAD screening in high cardiovascular risk patients, helping to the early diagnosis of asymptomatic AAA.