Green conversion of hazardous red mud into diagnostic X-ray shielding tiles.

Red mud is a solid hazardous alumina industrial waste, which is rich in iron, titanium, aluminum, silicon, calcium, etc. The red mud contains 30-60% of hematite, which is suitable for shielding high energy X- and gamma rays. So, the iron rich red mud was converted into diagnostic X-ray shielding tiles through ceramic route by adding a certain weight percentage of BaSO4 and binders (kaolin clay or sodium hexametaphosphate) with it. The kaolin clay tile possess sufficient impact strength (failure point is 852 mm for 19 mm steel ball) and flexural strength of ~25 N/mm2, which is suitable for wall applications. The 10.3 mm and 14.7 mm thick red mud:BaSO4:kaolin clay tile possess the attenuation equivalent to 2 mm and 2.3 mm lead at 125 kVp and 140 kVp, respectively. No heavy elements were found to leach out except chromium and arsenic from the sintered tiles. However, the leaching of Cr (0.6 ppm) and As (0.015 ppm) was found to be well below the permissible limit. These tiles can be used in the X-ray diagnosis, CT scanner, bone densitometry, and cath labs instead of toxic lead sheet and thereby to protect the operating personnel, public, and environment from radiation hazards.

Rapid diagnosis of SARS-CoV-2 using potential point-of-care electrochemical immunosensor: Toward the future prospects.

Coronavirus disease (COVID-19) is an emerging and highly infectious disease making global public health concern and socio-economic burden. It is caused due to Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2). It has the tendency to spread rapidly through person-to-person. Currently, several molecular diagnostic platforms such as PCR, qRT-PCR, reverse transcription loop-mediated isothermal amplification (RT-LAMP), CRISPR are utilized for the diagnosis of SARS-CoV-2. These conventional techniques are costly, time consuming and require sophisticated instrumentation facility with well trained personnel for testing. Hence, it is tough to provide testing en-masse to the people in developing countries. On the other hand, several serological biosensors such as lateral flow immunosensor, optical, electrochemical, microfluidics integrated electrochemical/fluorescence is currently utilized for the diagnosis of SARS-CoV-2. In current pandemic situation, there is an urgent need of rapid and efficient diagnosis on mass scale of SARS-CoV-2 for early stage detection. Early monitoring of viral infections can help to control and prevent the spreading of infections in large chunk of population. In this review, the SARS-CoV-2 and their biomarkers in biological samples, collection of samples and recently reported potential electrochemical immunosensors for the rapid diagnosis of SARS-CoV-2 are discussed.

Biosensor-based diagnostic approaches for various cellular biomarkers of breast cancer: A comprehensive review.

Breast cancer is the most commonly occurring cancer among women which leads to thousands of deaths worldwide. The chances of survival are more if the breast cancer is diagnosed at early stage. At present, mammography, magnetic resonance imaging, ultrasound and tissue biopsies are the main diagnostic techniques available for the detection of breast cancer. However, despite of offering promising results, requirement of expensive setup, skilled supervision, expert analysis, invasive procedure (biopsy) and low capacity of multiplexing are the main limitations of these diagnostic techniques. Due to high cost, these screening tests are out of reach of people belonging to low socioeconomic groups and this poses serious health burden to the society. Recently, biosensor-based diagnostic technology for early detection of various types of cancers and other non-oncological disorders have gained considerable attention because of their several advantageous features over existing diagnostic technologies such as high throughput, noninvasive nature, cost effectiveness, easy interpretable results and capacity for multiplexing. Further, biosensors can be designed for biomarkers which are confined to particular type of cancer. In this review, we have discussed about various genomic, transcriptomic, proteomic and metabolomic biomarkers associated with breast cancer, various biosensors-based diagnostic approaches designed for detection of specific biomarkers associated with breast cancer are also described. Further, this review throws insight on various biomarkers linked with breast cancer which can be effectively exploited to develop new diagnostic technology. The assessment of these biomarkers associated with BC using biosensors in large population are cost-effective, non-invasive and high throughput. They help in risk assessment of disease at very initial stage even in backward areas and also help to lower the disease burden of society and economic cost of treatment for a common man. This review would provide new avenues for the development of biosensor based diagnostic technology for the detection of biomarkers associated with breast cancer.

Point-of-Care Biosensor-Based Diagnosis of COVID-19 Holds Promise to Combat Current and Future Pandemics.

Efficient and rapid detection of viruses plays an extremely important role in disease prevention, diagnosis, and environmental monitoring. Early screening of viral infection among the population has the potential to combat the spread of infection. However, the traditional methods of virus detection being used currently, such as plate culturing and quantitative RT-PCR, give promising results, but they are time-consuming and require expert analysis and costly equipment and reagents; therefore, they are not affordable by people in low socio-economic groups in developing countries. Further, mass or bulk testing chosen by many governments to tackle the pandemic situation has led to severe shortages of testing kits and reagents and hence are affecting the demand and supply chain drastically. We tried to include all the reported current scenario-based biosensors such as electrochemical, optical, and microfluidics, which have the potential to replace mainstream diagnostic methods and therefore could pave the way to combat COVID-19. Apart from this, we have also provided information on commercially available biosensors for detection of SARS-CoV-2 along with the challenges in development of better diagnostic approaches. It is therefore expected that the content of this review will help researchers to design and develop more sensitive advanced commercial biosensor devices for early diagnosis of viral infection, which can open up avenues for better and more specific therapeutic outcomes.

Au/NiFe2O4 nanoparticle-decorated graphene oxide nanosheets for electrochemical immunosensing of amyloid beta peptide.

In the present work, an electrochemical immunosensor has been fabricated for the detection of amyloid beta peptide (ßA1--42) based on a gold nanoparticle/nickel ferrite decorated graphene oxide-chitosan nanocomposite (Au/NiFe2O4@GO-Ch) modified glassy carbon electrode (GCE) as an effective sensing platform. ßA1-42 has been analyzed as a potential biomarker for its application in Alzheimer's disease monitoring. The combination of highly conducting Au and NiFe2O4 nanoparticles on two-dimensional GO nanosheets provides an excellent platform for sensitive and selective sensing applications. A miniaturized Au/NiFe2O4@GO-Ch/GCE immunosensor was prepared by immobilization of ßA antibody onto Au//NiFe2O4@GO-Ch/GCE via carbodiimide coupling. Various characterization techniques were utilized in the study to estimate the morphological and electronic attributes of the components used to fabricate the immunosensor. Differential pulse voltammetry (DPV) was performed to study the amperometric response of the developed immunosensor as a function of ßA1-42 concentration. The DPV results confirmed that the immunosensor detected ßA1-42 selectively and demonstrated a wide linear range from 1 pg mL-1 to 1 ng mL-1 and a detection limit of 3.0 pg mL-1. Furthermore, the immunosensor also indicated its clinical viability by detecting ßA1-42 in cerebrospinal fluid.

Fast separation and sensitive detection of carcinogenic aromatic amines by reversed-phase micro-liquid chromatography coupled with electrochemical detection.

A micro-LC method was developed for the fast and sensitive analysis of aromatic amines by electrochemical detection. The chromatographic separation of nine carcinogenic aromatic amines was performed on an ABZ + PLUS column with detection limits up to pM L(-1) levels. Mobile phase comprised of methanol-acetate buffer of pH 5 (45:55, v/v) used at a flow rate of 0.2 ml min(-1). The detection was performed with a 6 mm glassy carbon electrode at an applied potential of 0.8 V versus Ag/AgCl. An intraday RSD for retention time and peak area were between 0.22% and 0.73% and 1.86% and 4.03%, respectively. The interdays RSD for retention time and peak area were between 0.47% and 1.35% and 2.04% and 4.42%, respectively. The applicability of the assay has been demonstrated by analyzing these aromatic amines in lake water and synthetic food colour additives. A comparison is given between electrochemical and UV detection.