Advances in xanthine biosensors and sensors: A review.

Xanthine is derived from hypoxanthine by xanthine oxidase (XOD), a flavoprotein containing molybdenum and non-haem iron, sulfur and from guanine by guanine deaminase enzyme. Xanthine is oxidized into uric acid by XOD. Xanthine is used as an indicator of fish freshness, based on the reactions in which ATP is degraded into xanthine and its quantity increases with time of fish death.

An impedimetric immunosensor based on chitosan-Au nanoparticles-reduced graphene oxide nanosheet composite modified PG electrode for detection of brain natriuretic peptide.

Unlabelled: An ultrasensitive impedimetric immunosensor was developed to detect brain natriuretic peptide (BNP) for early diagnosis of heart failure. To construct this immunosensor, anti-BNP antibodies were immobilized covalently onto nanocomposite of chitosan-Au nanoparticles and reduced graphene oxide nanosheets (CHIT-Au@rGONs) electrodeposited onto pencil graphite electrode. This approach impedes charge transfer resistance (Rct) value proportionally to the BNP captured by antigen-antibody interactions.

An Amperometric Acetylcholine Biosensor Based on Co-Immobilization of Enzyme Nanoparticles onto Nanocomposite.

An electrochemical biosensor was fabricated using nanoparticles of acetylcholinesterase (AChE) and choline oxidase (ChO)/Pt nanoparticles (PtNPs)/porous graphene oxide nanosheet (GONS) composite. A pencil graphite electrode (PGE) was used for the electrodeposition of nanocomposite and the determination of acetylcholine (ACh), a neurotransmitter. Various techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectra and cyclic voltammetry (CV) were used for characterization.

Electrochemical Sensor for Bilirubin Detection Using Paper-Based Screen-Printed Electrodes Functionalized with Silver Nanoparticles.

A notable diagnostic for the detection of hemolytic diseases is bilirubin, a by-product of haemoglobin breakdown. The concentration of bilirubin ranges from 0.3 to 1.

Assessment of snout analysis of Himalayan glaciers: impact studies on Pindari, Kafni, Sundardhunga, and Baljuri base camp glaciers.

There are several causes for the increasing rate of deglaciation, such as global warming, increase in the concentration of black carbon, and extensive use of fossil fuels which causes the change in the overall climate system and shifting glacier ecosystem. This study was conducted on Pindari valley glaciers part of lesser Himalaya in Uttarakhand. This study investigates to (1) monitor and map change in the frontal length or the snout region of a glacier that can be studied with the help of remote sensing techniques and (2) evaluate the decadal and annual retreat rate of the glacier from 1972 to 2018.

Impact of climate on vegetation in Pindari watershed of Western Himalayas, Kumaun, India, using spatiotemporal analysis: 1972-2018.

Vegetation dynamics is an important aspect for determining climate change trends. The present study delineates to examine spatiotemporal changes of vegetation cover in Pindari valley (Kumaun Himalaya) from the 1972 to 2018 timeline. The study includes the calculation of vegetation spectral indices of normalized vegetation index (NDVI), extraction of different vegetation classes, and statistical analysis of the Mann-Kendall (MK) test on historical metrological data (especially precipitation and temperature) of the study site.

Amperometric detection of tumor suppressor protein p53 via pencil graphite electrode for fast cancer diagnosis.

Cancer occupies the second place in terms of worldwide mortality. Early and fast diagnosis of cancer helps clinicians to expand therapeutic approaches ultimately leading towards early diagnosis of cancer patients. In the present work, we delineated an amperometric immunosensor to diagnose cancer to detect p53, a biomarker for cancer.

A Novel Amperometric Genosensor for Rapid Detection of Canine Parvovirus in Feces.

A highly sensitive novel amperometric genosensor has been developed for rapid detection of canine parvovirus (CPV) DNA in fecal swabs of naturally infected dogs. The genosensor is based on a single stranded 5°-thiolated (SH) DNA probe complementary to VP1/VP2 gene of canine parvo vaccine strain, immobilized covalently on a polycrystalline gold (Au) electrode. The genosensor has been characterized by scanning electron microscopy (SEM), Fourier Transform Infra-Red Spectroscopy (FTIR), cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectra (EIS).

A comprehensive review of methods for determination of l-lysine with detailed description of biosensors.

l-lysine being one of the essential amino acids is not produced by the body, but is obtained through diet. l-lysine determination is important in the food and pharmaceutical industries as well as have medical and diagnostic applications. The normal l-lysine levels in a healthy human serum sample is 150 to 250 μmol/l.

The Prevalence of Polycystic Ovary Syndrome: A Brief Systematic Review.

Background: Polycystic ovary syndrome (PCOS), the major endocrinopathy among reproductive-aged women, is not yet perceived as an important health problem in the world. It affects 4%-20% of women of reproductive age worldwide. The prevalence, diagnosis, etiology, management, clinical practices, psychological issues, and prevention are some of the most confusing aspects associated with PCOS.

A changing trend in diagnostic methods of Influenza A (H3N2) virus in human: a review.

The influenza virus is classified into four types A, B, C, and D, but type A and B are responsible for major illnesses in people with influenza A being the only virus responsible for flu pandemics due to the presence of two surface proteins called hemagglutinin (H) and neuraminidase (N) on the virus. The two subtypes of influenza A virus, H1N1 and H3N2, have been known to cause many flu pandemics. Both subtypes change genetically and antigenically to produce variants (clades and subclades, also know as groups and subgroups).

Electrochemical Multiplexed Paper Nanosensor for Specific Dengue Serotype Detection Predicting Pervasiveness of DHF/DSS.

The serotype-specific early detection of dengue fever is very effective in predicting the pervasiveness of fatal infections such as dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). This fever results from reinfection (secondary) with a serotype of the dengue virus, which is different from the serotype involved in primary infection. Hence, the present work was aimed to develop a multiplexed electrochemical paper-based analytical device (ePAD) consisting of graphene oxide-silicon dioxide (GO-SiO) nanocomposites to detect the specific type of dengue virus (DENV).

Organic Polymer and Metal Nano-particle Based Composites for Improvement of the Analytical Performance of Electrochemical Biosensors.

Metal nanoparticles (NPs) are described in the nanoscale and made from either pure metals or their compounds such as oxides. Metallic NPs have certain indistinct functional groups due to which these can bind with any type of ligand, antibody and drugs. Organic polymers, which conduct electricity, are called conducting polymers (intrinsically conducting polymers).

Detection methods for influenza A H1N1 virus with special reference to biosensors: a review.

H1N1 (Swine flu) is caused by influenza A virus, which is a member of Orthomyxoviridae family. Transmission of H1N1 occurs from human to human through air or sometimes from pigs to humans. The influenza virus has different RNA segments, which can reassert to make new virus strain with the possibility to create an outbreak in unimmunized people.

Fabrication and application of an amperometric lysine biosensor based on covalently immobilized lysine oxidase nanoparticles onto Au electrode.

The fabrication of an amperometric lysine biosensor is described in this study, wherein nanoparticles (NPs) of lysine oxidase (LOx) are covalently immobilized onto gold electrode (AuE). The LOxNPs were prepared by desolvation method and characterized by UV Vis spectroscopy, Fourier transform infra red (FTIR) spectroscopy and transmission electron microscopy (TEM). The LOxNPs/AuE modified working electrode was studied by scanning electron microscope (SEM) and cyclic voltammetric (CV) techniques.

Fabrication of an improved amperometric creatinine biosensor based on enzymes nanoparticles bound to Au electrode.

An improved amperometric creatinine biosensor was fabricated that dependent on covalent immobilisation of nanoparticles of creatininase (CANPs), creatinase (CINPs) and sarcosine oxidase (SOxNPs) onto gold electrode (AuE). The CANPs/CINPs/SOxNPs/AuE was characterised by scanning electron microscopy and cyclic voltammetry at various stages. The working electrode exhibited optimal response within 2 s at a potential of 0.

Detection of tumor suppressor protein p53 with special emphasis on biosensors: A review.

Cancer is a general word, which specifies a cluster of diseases affecting almost every-body part. Cancer is a second leading cause of death, globally. The tumor suppressor protein p53 is known to play a vital role in prevention of cancer.

Bio-sensing of organophosphorus pesticides: A review.

Organophosphorus (OP) pesticides have been used widely as agricultural and household pest control agents for almost five decades and persist in our water resources, fruits, vegetables and processed food as health and environmental hazardous compounds. Thus, detection of these harmful OP pesticides at an ease with high sensitivity and selectivity is the need of hour. Bio-sensing technology meet these requirements and has been employed at a large scale for detection.

Quantitative analysis of sarcosine with special emphasis on biosensors: a review.

The quantitative determination of sarcosine is of great importance in clinical chemistry, food and fermentation industries. Elevated sarcosine levels are associated with Alzheimer, dementia, prostate cancer, colorectal cancer, stomach cancer and sarcosinemia. This review summarizes the various methods for quantitative analysis of sarcosine with special emphasis on various strategies of biosensors and their analytical performance.

Prussian blue nanocubes/carbon nanospheres heterostructure composite for biosensing of metformin.

This paper reports the fabrication of highly sensitive metformin sensor based on Prussian blue (PB) nanocubes/carbon nanosphere (CNS) heterostructures composed of a perfect cube and spherical composite on a fluorine-doped tin oxide surface. Due to the excellent biocompatibility of PB nanocubes the PB/CNS based Mf sensor exhibited a wide linear range of 0.001-10 mM with a response duration of less than 5 s and a detection limit (based on signal to noise ratio) of 0.

Correction to: Voltammetric detection of anti-HIV replication drug based on novel nanocomposite gold-nanoparticle-CaCO hybrid material.

The Figs. 2, 4 and 5 were published wrongly in this paper, due to inadvertent compilation of figures during uploading the paper.

An improved enzyme nanoparticles based amperometric pyruvate biosensor for detection of pyruvate in serum.

The nanoparticles of commercially available pyruvate oxidase (POx) from Aerococcus species were prepared by desolvation method, which were then characterized and covalently immobilized onto gold electrode (AuE) to construct an improved model of amperometric pyruvate biosensor. The POxNPs/Au electrode was analyzed morphologically by scanning electron microscopy (SEM). On the other hand, cyclic voltammetry studies (CV) and electrochemical impedance spectroscopy (EIS) helped in deciphering the electrochemical properties of the electrode at different stages of construction.

Development of glycerol biosensor based on co-immobilization of enzyme nanoparticles onto graphene oxide nanoparticles decorated pencil graphite electrode.

An improved amperometric biosensor was fabricated by immobilizing glycerol kinase (GK) and glycerol-3-phosphate oxidase (GPO) nanoparticles (NPs) onto graphene oxide nanoparticles (GrONPs) modified pencil graphite (PG) electrode. The GKNPs, GPONPs and GrONPs were characterized by UV spectroscopy, and transmission electron microscopy (TEM). The working electrode (GKNPs/GPONPs/GrONPs/PGE) was characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques.

Biosensing methods for determination of creatinine: A review.

Creatinine is a metabolic product of creatine phosphate in muscles, which provides energy to muscle tissues. Creatinine has been considered as indicator of renal function specifically after dialysis, thyroid malfunction and muscle damage. The normal level of creatinine in the serum and its excretion through urine in apparently healthy individuals is 45-140 μM and 0.