Conductometric immunosensor for specific Escherichia coli O157:H7 detection on chemically funcationalizaed interdigitated aptasensor.

Escherichia coli O157:H7 is a strain of Escherichia coli known for causing foodborne illness through the consumption of contaminated or raw food. To detect this pathogen, a conductometric immunosensor was developed using a conductometric sensing approach. The sensor was constructed on an interdigitated electrode and modified with a monoclonal anti-Escherichia coli O157:H7 aptamer. A total of 200 electrode pairs were fabricated and modified to bind to the target molecule replica. The binding replica, acting as the bio-recognizer, was linked to the electrode surface using 3-Aminopropyl triethoxysilane. The sensor exhibited excellent performance, detecting Escherichia coli O157:H7 in a short time frame and demonstrating a wide detection range of 1 fM to 1 nM. Concentrations of Escherichia coli O157:H7 were detected within this range, with a minimum detection limit of 1 fM. This innovative sensor offers simplicity, speed, high sensitivity, selectivity, and the potential for rapid sample processing. The potential of this proposed biosensor is particularly beneficial in applications such as drug screening, environmental monitoring, and disease diagnosis, where real-time information on biomolecular interactions is crucial for timely decision-making and where cross-reactivity or interference may compromise the accuracy of the analysis.

Micro-interdigitated electrodes genosensor based on Au-deposited nanoparticles for early detection of cervical cancer.

Genosensor-based electrodes mediated with nanoparticles (NPs) have tremendously developed in medical diagnosis. Herein, we report a facile, rapid, low cost and highly sensitive biosensing strategy for early detection of HPV 18 using gold-nanoparticles (AuNPs) deposited on micro-IDEs. This study represents surface charge transduction of micro-interdigitated electrodes (micro-IDE) alumina insulated with silica, independent and mini genosensor modified with colloidal gold NPs (AuNPs), and determination of gene hybridization for early detection of cervical cancer. The surface of AuNPs deposited micro-IDE functionalized with optimized 3-aminopropyl-triethoxysilane (APTES) followed by hybridization with deoxyribonucleic acid (DNA) virus to develop DNA genosensor. The results of ssDNA hybridization with the ssDNA target of human papillomavirus (HPV) 18 have affirmed that micro-IDE functionalized with colloidal AuNPs resulted in the lowest detection at 0.529 aM. Based on coefficient regression, micro-IDE functionalized with AuNPs produces better results in the sensitivity test (R2 = 0.99793) than unfunctionalized micro-IDE.

An update on pathogenesis and clinical scenario for Parkinson's disease: diagnosis and treatment.

In severe cases, Parkinson's disease causes uncontrolled movements known as motor symptoms such as dystonia, rigidity, bradykinesia, and tremors. Parkinson's disease also causes non-motor symptoms such as insomnia, constipation, depression and hysteria. Disruption of dopaminergic and non-dopaminergic neural networks in the substantia nigra pars compacta is a major cause of motor symptoms in Parkinson's disease. Furthermore, due to the difficulty of clinical diagnosis of Parkinson's disease, it is often misdiagnosed, highlighting the need for better methods of detection. Treatment of Parkinson's disease is also complicated due to the difficulties of medications passing across the blood-brain barrier. Moreover, the conventional methods fail to solve the aforementioned issues. As a result, new methods are needed to detect and treat Parkinson's disease. Improved diagnosis and treatment of Parkinson's disease can help avoid some of its devastating symptoms. This review explores how nanotechnology platforms, such as nanobiosensors and nanomedicine, have improved Parkinson's disease detection and treatment. Nanobiosensors integrate science and engineering principles to detect Parkinson's disease. The main advantages are their low cost, portability, and quick and precise analysis. Moreover, nanotechnology can transport medications in the form of nanoparticles across the blood-brain barrier. However, because nanobiosensors are a novel technology, their use in biological systems is limited. Nanobiosensors have the potential to disrupt cell metabolism and homeostasis, changing cellular molecular profiles and making it difficult to distinguish sensor-induced artifacts from fundamental biological phenomena. In the treatment of Parkinson's disease, nanoparticles, on the other hand, produce neurotoxicity, which is a challenge in the treatment of Parkinson's disease. Techniques must be developed to distinguish sensor-induced artifacts from fundamental biological phenomena and to reduce the neurotoxicity caused by nanoparticles.

An Update on Parkinson's Disease and its Neurodegenerative Counterparts.

INTRODUCTION: Neurodegenerative disorders are a group of diseases that cause nerve cell degeneration in the brain, resulting in a variety of symptoms and are not treatable with drugs. Parkinson's disease (PD), prion disease, motor neuron disease (MND), Huntington's disease (HD), spinal cerebral dyskinesia (SCA), spinal muscle atrophy (SMA), multiple system atrophy, Alzheimer's disease (AD), spinocerebellar ataxia (SCA) (ALS), pantothenate kinase-related neurodegeneration, and TDP-43 protein disorder are examples of neurodegenerative diseases. Dementia is caused by the loss of brain and spinal cord nerve cells in neurodegenerative diseases. BACKGROUND: Even though environmental and genetic predispositions have also been involved in the process, redox metal abuse plays a crucial role in neurodegeneration since the preponderance of symptoms originates from abnormal metal metabolism. METHOD: Hence, this review investigates several neurodegenerative diseases that may occur symptoms similar to Parkinson's disease to understand the differences and similarities between Parkinson's disease and other neurodegenerative disorders based on reviewing previously published papers. RESULTS: Based on the findings, the aggregation of alpha-synuclein occurs in Parkinson's disease, multiple system atrophy, and dementia with Lewy bodies. Other neurodegenerative diseases occur with different protein aggregation or mutations. CONCLUSION: We can conclude that Parkinson's disease, Multiple system atrophy, and Dementia with Lewy bodies are closely related. Therefore, researchers must distinguish among the three diseases to avoid misdiagnosis of Multiple System Atrophy and Dementia with Lewy bodies with Parkinson's disease symptoms.

Fabrication of Silicon Nanowire Sensors for Highly Sensitive pH and DNA Hybridization Detection.

A highly sensitive silicon nanowire (SiNW)-based sensor device was developed using electron beam lithography integrated with complementary metal oxide semiconductor (CMOS) technology. The top-down fabrication approach enables the rapid fabrication of device miniaturization with uniform and strictly controlled geometric and surface properties. This study demonstrates that SiNW devices are well-aligned with different widths and numbers for pH sensing. The device consists of a single nanowire with 60 nm width, exhibiting an ideal pH responsivity (18.26 × 106 Ω/pH), with a good linear relation between the electrical response and a pH level range of 4-10. The optimized SiNW device is employed to detect specific single-stranded deoxyribonucleic acid (ssDNA) molecules. To use the sensing area, the sensor surface was chemically modified using (3-aminopropyl) triethoxysilane and glutaraldehyde, yielding covalently linked nanowire ssDNA adducts. Detection of hybridized DNA works by detecting the changes in the electrical current of the ssDNA-functionalized SiNW sensor, interacting with the targeted ssDNA in a label-free way. The developed biosensor shows selectivity for the complementary target ssDNA with linear detection ranging from 1.0 × 10-12 M to 1.0 × 10-7 M and an attained detection limit of 4.131 × 10-13 M. This indicates that the use of SiNW devices is a promising approach for the applications of ion detection and biomolecules sensing and could serve as a novel biosensor for future biomedical diagnosis.

Gold-Nanohybrid Biosensors for Analyzing Blood Circulating Clinical Biomacromolecules: Current Trend toward Future Remote Digital Monitoring.

Mortality level is worsening the situation worldwide thru blood diseases and greatly jeopardizes the human health with poor diagnostics. Due to the lack of successful generation of early diagnosis, the survival rate is currently lower. To overcome the present hurdle, new diagnostic methods have been choreographed for blood disease biomarkers analyses with the conjunction of ultra-small ideal gold nanohybrids. Gold-hybrids hold varieties of unique features, such as high biocompatibility, increased surface-to-volume ratio, less-toxicity, ease in electron transfer and have a greater localized surface plasmon resonance. Gold-nanocomposites can be physically hybrid on the sensor surface and functionalize with the biomolecules using appropriate chemical conjugations. Revolutionizing biosensor platform can be prominently linked for the nanocomposite applications in the current research on medical diagnosis. This review encloses the new developments in diagnosing blood biomarkers by utilizing the gold-nanohybrids. Further, the current state-of-the-art and the future envision with digital monitoring for facile telediagnosis were narrated.

Designing DNA probe from HPV 18 and 58 in the E6 region for sensing element in the development of genosensor-based gold nanoparticles.

The E6 region has higher protuberant probability annealing than consensus probe focusing on another region in the human papillomavirus (HPV) genome in terms of detection and screening method. Here, we designed the first multiple virus single-stranded deoxyribonucleic acid (ssDNA) for multiple detections in an early phase of screening for cervical cancer in the E6 region and became a fundamental evolution of detection electrochemical HPV biosensor. Gene profiling of the virus ssDNA sequences has been carried by high-end bioinformatics tools such as GenBank, Basic Local Alignment Searching Tools (BLAST), and Clustal OMEGA in a row. The output from bioinformatics tools resulted in 100% of similarities between our virus ssDNA probe and HPV complete genome in the databases. The cross-validation between HPV genome and our designed virus ssDNA provided high specificity and selectivity during screening methods compared with Pap smear. The DNA probe for HPV 18, 5' COOH-GAT CCA GAA GGT ACA GAC GGG GAG GGC ACG 3', while 5'COOH-GGG CGC TGT GCA GTG TGT TGG AGA CCC CGA3' as DNA probe for HPV 58 designed with 66.77% guanine (G) and cytosine (C) content for both. Our virus ssDNA probe for the HPV biosensor promises high sensitivity, specificity, selectivity, repeatability, low fluid consumption, and will be useful in mini-size diagnostic devices for cervical cancer detection.

MicroRNA of N-region from SARS-CoV-2: Potential sensing components for biosensor development.

An oligonucleotide DNA probe has been developed for the application in the DNA electrochemical biosensor for the early diagnosis of coronavirus disease (COVID-19). Here, the virus microRNA from the N-gene of severe acute respiratory syndrome-2 (SARS-CoV-2) was used for the first time as a specific target for detecting the virus and became a framework for developing the complementary DNA probe. The sequence analysis of the virus microRNA was carried out using bioinformatics tools including basic local alignment search tools, multiple sequence alignment from CLUSTLW, microRNA database (miRbase), microRNA target database, and gene analysis. Cross-validation of distinct strains of coronavirus and human microRNA sequences was completed to validate the percentage of identical and consent regions. The percent identity parameter from the bioinformatics tools revealed the virus microRNAs' sequence has a 100% match with the genome of SARS-CoV-2 compared with other coronavirus strains, hence improving the selectivity of the complementary DNA probe. The 30 mer with 53.0% GC content of complementary DNA probe 5' GCC TGA GTT GAG TCA GCA CTG CTC ATG GAT 3' was designed and could be used as a bioreceptor for the biosensor development in the clinical and environmental diagnosis of COVID-19.

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.

Novel Approaches in Fabrication and Integration of Nanowire for Micro/Nano Systems.

Nanowires have been utilized widely in the generation of high-performance nanosensors. Laser ablation, chemical vapor, thermal evaporation and alternating current electrodeposition are in use in developing nanowires. Nanowires are in a great attention because of their submicron feature and their potentials in the front of nanoelectronics, accelerated field effect transistors, chemical- and bio-sensors, and low power consuming light-emitting devices. With the control of nanowire size and concentration of dopant, the electrical sensitivity and other properties of nanowires can be tuned for the reproducibility. Nanowires comprise of arrays of electrodes that form a nanometer electrical circuit. One of advantages of nanowires is that they can be fabricated in nanometer-size for various applications in different approaches. Several studies have been conducted on nanowires and researchers discovered that nanowires have the potential in the applications with material properties at the nanometer scale. The unique electrical properties of nanowires have made them to be promising for numerous applications. Nowadays, for example, MOS field-effect transistors are largely used as fundamental building elements in electronic circuits. Also, the dimension of MOS transistors is gradually decreasing to the nanoscale based on the prediction made by Moor's law. However, their fabrication is challenging. This review summarized different techniques in the fabrication of nanowires, global nanowire prospect, testing of nanowires to understand the real electrical behavior using higher resolution microscopes, and brief applications in the detection of biomolecules, disease such as corona viral pandemic, heavy metal in water, and applications of nanowires in agriculture.

Silica and graphene mediate arsenic detection in mature rice grain by a newly patterned current-volt aptasensor.

Arsenic is a major global threat to the ecosystem. Here we describe a highly accurate sensing platform using silica nanoparticles/graphene at the surface of aluminum interdigitated electrodes (Al IDE), able to detect trace amounts of arsenic(III) in rice grain samples. The morphology and electrical properties of fabricated Al IDEs were characterized and standardized using AFM, and SEM with EDX analyses. Micrometer scale Al IDEs were fabricated with silicon, aluminum, and oxygen as primary elements. Validation of the bare Al IDE with electrolyte fouling was performed at different pH levels. The sensing surface was stable with no electrolyte fouling at pH 7. Each chemical modification step was monitored with current-volt measurement. The surface chemical bonds were characterized by fourier transform infrared spectroscopy (FTIR) and revealed different peaks when interacting with arsenic (1600-1000 cm-1). Both silica nanoparticles and graphene presented a sensitive limit of detection as measured by slope calibration curves at 0.0000001 pg/ml, respectively. Further, linear regression was established using ΔI (A) = 3.86 E-09 log (Arsenic concentration) [g/ml] + 8.67 E-08 [A] for silica nanoparticles, whereas for graphene Y = 3.73 E-09 (Arsenic concentration) [g/ml] + 8.52 E-08 on the linear range of 0.0000001 pg/ml to 0.01 pg/ml. The R2 for silica (0.96) and that of graphene (0.94) was close to the maximum (1). Modification with silica nanoparticles was highly stable. The potential use of silica nanoparticles in the detection of arsenic in rice grain extract can be attributed to their size and stability.

Production and characterization of graphene from carbonaceous rice straw by cost-effect extraction.

This paper describes the synthesis of graphene-based activated carbon from carbonaceous rice straw fly ash in an electrical furnace and the subsequent potassium hydroxide extraction. The produced graphene has a proper morphological structure; flakes and a rough surface can be observed. The average size of the graphene was defined as up to 2000 nm and clarification was provided by high-resolution microscopes (FESEM and FETEM). Crystallinity was confirmed by surface area electron diffraction. The chemical bonding from the graphene was clearly observed, with -C=C- and O-H stretching at peaks of 1644 cm-1 and 3435 cm-1, respectively. Impurities in the graphene were found using X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy. The measured size, according to zeta-potential analysis, was 8722.2 ± 25 nm, and the average polydispersity index was 0.576. The stability of the mass reduction was analyzed by a thermogravimetric at 100 °C, with a final reduction of ~ 11%.

Distinguishing normal and aggregated alpha-synuclein interaction on gold nanorod incorporated zinc oxide nanocomposite by electrochemical technique.

Misfolding and accumulation of the protein alpha synuclein in the brain cells characterize Parkinson's disease (PD). Electrochemical based aluminum interdigitated electrodes (ALIDEs) was fabricated by using conventional photolithography method and modified the surfaces with zinc oxide and gold nanorod by using spin coating method for the analysis of PD protein biomarker. The device surface modified with gold nanorod of 25 nm diameter was used. The bare devices and the surface modified devices were characterized by Scanning Electron Microscope, 3D-Profilometer, Atomic Force Microscope and high-power microscope. The above measurement was also performed to measure the interaction of antibody with aggregated alpha-synuclein for normal, aggregated and aggregated alpha synuclein in human serum and distinguished against 3 control proteins (PARK1, DJ-1 and Factor IX). The detection limit for normal alpha synuclein was 1 f. with the sensitivity of 1 f. on a linear regression (R2 = 0.9759). The detection limit for aggregated alpha synuclein was 10 aM with the sensitivity of 1 aM on a linear regression (R2 = 0.9797). Also, the detection limit of aggregated alpha synuclein in serum was 10 aM with the sensitivity of 1 aM on a linear regression (R2 = 0.9739). These results however indicate that, serum has only minimal amount of alpha synuclein.

Production and characterization of silica nanoparticles from fly ash: conversion of agro-waste into resource.

A chemical method to synthesize amorphous silica nanoparticles from the incinerated paddy straw has been introduced. The synthesis was conducted through the hydrolysis by alkaline-acidic treatments. As a result, silica particles produced with the sizes were ranging at 60-90 nm, determined by high-resolution microscopy. The crystallinity was confirmed by surface area electron diffraction. Apart from that, chemical and diffraction analyses for both rice straw ash and synthesized silica nanoparticles were conducted by X-ray diffraction and Fourier-transform infrared spectroscopy. The percentage of silica from the incinerated straw was calculated to be 28.3. The prominent surface chemical bonding on the generated silica nanoparticles was with Si-O-Si, stretch of Si-O and symmetric Si-O bonds at peaks of 1090, 471, and 780 cm-1, respectively. To confirm the impurities of the elements in the produced silica, were analyzed using X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy. The stability of silica nanoparticles was investigated using thermogravimetric analysis and zeta potential. The measured size from zeta potential analysis was 411.3-493 nm and the stability of mass reduction was located at 200 °C with final amount of mass reduced ∼88% and an average polydispersity Index was 0.195-0.224.

Voltammetric determination of human papillomavirus 16 DNA by using interdigitated electrodes modified with titanium dioxide nanoparticles.

A gene sensor for rapid detection of the Human Papillomavirus 16 (HPV 16) which is associated with the appearance of cervical cancer was developed. The assay is based on voltammetric determination of HPV 16 DNA by using interdigitated electrodes modified with titanium dioxide nanoparticles. Titanium dioxide nanoparticles (NPs) were used to modify a semiconductor-based interdigitated electrode (IDE). The surface of the NPs was then functionalized with a commercial 24-mer oligomer DNA probe for HPV 16 that was modified at the 5' end with a carboxyl group. If the probe interacts with the HPV 16 ssDNA, the current, best measured at a working voltage of 1.0 V, increases. The gene sensor has has a ∼ 0.1 fM limit of detection which is comparable to other sensors. The dielectric voltammetry analysis was carried out from 0 V to 1 V. The electrochemical sensitivity of the IDE is 2.5 × 10-5 µA·µM-1·cm-2. Graphical abstract Schematic of an interdigitated electrode (IDE) modified with titanium dioxide nanoparticles for voltammetric determination of HPV 16 DNA by using an appropriate DNA probe.

Human Papillomavirus E6 biosensing: Current progression on early detection strategies for cervical Cancer.

Prognosis of early cancer detection becomes one of the tremendous issues in the medical health system. Medical debates among specialist doctor and researcher in therapeutic approaches became a hot concern for cervix cancer deficiencies early screening, risk factors cross-reaction, portability device, rapid and free labeling system. The electrical biosensing based system showed credibility in higher specificity and selectivity due to hybridization of DNA duplex between analyte target and DNA probes. Electrical DNA sensor for cervix cancer has attracted too many attentions to researcher notification based on high performance, easy to handle, rapid system and possible to miniaturize. This review explores the current progression and future insignificant for HPV E6 genobiosensing for early Detection Strategies of Cervical Cancer.

Designing probe from E6 genome region of human Papillomavirus 16 for sensing applications.

Human Papillomavirus (HPV) is a standout amongst the most commonly reported over 100 types, among them genotypes 16, 18, 31 and 45 are the high-risk HPV. Herein, we designed the oligonucleotide probe for the detection of predominant HPV type 16 for the sensing applications. Conserved amino acid sequences within E6 region of the open reading frame in the HPV genome was used as the basis to design oligonucleotide probe to detect cervical cancer. Analyses of E6 amino acid sequences from the high-risk HPVs were done to check the percentage of similarity and consensus regions that cause different cancers, including cervical cancer. Basic local alignment search tools (BLAST) have given extra statistical parameters, for example, desire values (E-values) and score bits. The probe, 'GGG GTC GGT GGA CCG GTC GAT GTA' was designed with 66.7% GC content. This oligonucleotide probe is designed with the length of 24 mer, GC percent is between 40 and 70, and the melting point (Tm) is above 50°C. The probe needed an acceptable length between 22 and 31 mer. The choice of region is identified here can be used as a probe, has implications for HPV detection techniques in biosensor especially for clinical determination of cervical cancer.

Mediatorless Impedance Studies with Titanium Dioxide Conjugated Gold Nanoparticles for Hydrogen Peroxide Detection.

An impedimetric-based biosensor constructed using gold nanoparticles (AuNP) entrapped within titanium dioxide (TiO2) particles for hydrogen peroxide (H2O2) detection is the main feature of this research. The matrix of the biosensor employed the surface of TiO2, which was previously modified with an amine terminal group using 3-Aminopropyltriethoxysilane (APTS) at a low temperature to create a ready to immobilise surface for the biosensor application. Hemoglobin (Hb), which exhibits peroxidase-like activity, was used as the bioreceptor in the biosensor to detect H2O2 in solution. The analysis was carried out using an alternative impedance method, in which the biosensor exhibited a wide linear range response between 1 × 10-4 M and 1.5 × 10-2 M and a limit of detection (LOD) of 1 × 10-5 M without a redox mediator.

DNA extraction on bio-chip: history and preeminence over conventional and solid-phase extraction methods.

This review covers a developmental progression on early to modern taxonomy at cellular level following the advent of electron microscopy and the advancement in deoxyribonucleic acid (DNA) extraction for expatiation of biological classification at DNA level. Here, we discuss the fundamental values of conventional chemical methods of DNA extraction using liquid/liquid extraction (LLE) followed by development of solid-phase extraction (SPE) methods, as well as recent advances in microfluidics device-based system for DNA extraction on-chip. We also discuss the importance of DNA extraction as well as the advantages over conventional chemical methods, and how Lab-on-a-Chip (LOC) system plays a crucial role for the future achievements.

Multi-analyte validation in heterogeneous solution by ELISA.

Enzyme Linked Immunosorbent Assay (ELISA) is a standard assay that has been used widely to validate the presence of analyte in the solution. With the advancement of ELISA, different strategies have shown and became a suitable immunoassay for a wide range of analytes. Herein, we attempted to provide additional evidence with ELISA, to show its suitability for multi-analyte detection. To demonstrate, three clinically relevant targets have been chosen, which include 16kDa protein from Mycobacterium tuberculosis, human blood clotting Factor IXa and a tumour marker Squamous Cell Carcinoma antigen. Indeed, we adapted the routine steps from the conventional ELISA to validate the occurrence of analytes both in homogeneous and heterogeneous solutions. With the homogeneous and heterogeneous solutions, we could attain the sensitivity of 2, 8 and 1nM for the targets 16kDa protein, FIXa and SSC antigen, respectively. Further, the specific multi-analyte validations were evidenced with the similar sensitivities in the presence of human serum. ELISA assay in this study has proven its applicability for the genuine multiple target validation in the heterogeneous solution, can be followed for other target validations.