Malignancies and Biosensors: A Focus on Oral Cancer Detection through Salivary Biomarkers

Oral cancer is among the deadliest types of malignancy due to the late stage at which it is usually diagnosed, leaving the patient with an average five-year survival rate of less than 50%. The booming field of biosensing and point of care diagnostics can, in this regard, play a major role in the early detection of oral cancer. Saliva is gaining interest as an alternative biofluid for non-invasive diagnostics, and many salivary biomarkers of oral cancer have been proposed. While these findings are promising for the application of salivaomics tools in routine practice, studies on larger cohorts are still needed for clinical validation. This review aims to summarize the most recent development in the field of biosensing related to the detection of salivary biomarkers commonly associated with oral cancer. An introduction to oral cancer diagnosis, prognosis and treatment is given to define the clinical problem clearly, then saliva as an alternative biofluid is presented, along with its advantages, disadvantages, and collection procedures. Finally, a brief paragraph on the most promising salivary biomarkers introduces the sensing technologies commonly exploited to detect oral cancer markers in saliva. Hence this review provides a comprehensive overview of both the clinical and technological advantages and challenges associated with oral cancer detection through salivary biomarkers

Portable Bio-Devices: Design of Electrochemical Instruments from Miniaturized to Implantable Devices

The integration of biosensors and electronic technologies allows the development of biomedical systems able to diagnose and monitoring pathologies by detecting specific biomarkers. The chapter presents the main modules involved in the development of such devices, generically represented in Fig. 1, and focuses its attention on the essential components of these systems to address questions such as: how is the device powered? How does it communicate the measured data? What kind of sensors could be used?, and What kinds of electronics are used

Point-of-Care Devices for Viral Detection: COVID-19 Pandemic and Beyond

The pandemic of COVID-19 and its widespread transmission have made us realize the importance of early, quick diagnostic tests for facilitating effective cure and management. The primary obstacles encountered were accurately distinguishing COVID-19 from other illnesses including the flu, common cold, etc. While the polymerase chain reaction technique is a robust technique for the determination of SARS-CoV-2 in patients of COVID-19, there arises a high demand for affordable, quick, user-friendly, and precise point-of-care (POC) diagnostic in therapeutic settings. The necessity for available tests with rapid outcomes spurred the advancement of POC tests that are characterized by speed, automation, and high precision and accuracy. Paper-based POC devices have gained increasing interest in recent years because of rapid, low-cost detection without requiring external instruments. At present, microfluidic paper-based analysis devices have garnered public attention and accelerated the development of such POCT for efficient multistep assays. In the current review, our focus will be on the fabrication of detection modules for SARS-CoV-2. Here, we have included a discussion on various strategies for the detection of viral moieties. The compilation of these strategies would offer comprehensive insight into the detection of the causative agent preparedness for future pandemics. We also provide a descriptive outline for paper-based diagnostic platforms, involving the determination mechanisms, as well as a commercial kit for COVID-19 as well as their outlook

Application of Electrochemical Methods in Biosensing Technologies

Introducing biochemical factor to electronic devices have created a new branch of science. Recent development in biosensing technology enabled progress in pathogens detection. Currently, wide range of biomarkers (enzymes, peptides, DNA, microorganisms, etc. )recognize various target analytes, starting from basic metabolism changes to serious infections caused by pathogens. Improved sensitivity, selectivity and response time of sensors have instantly replaced traditional techniques. Easy handling, low production costs and miniaturization have met therapeutics need. Biosensing technologies are very strong point in telemedicine in public healthcare. This chapter will focus on electrochemical techniques for pathogens detection and show trending applications in biosensing technologies

NANOTECHNOLOGY FOR DETECTION OF DISEASES CAUSED BY VIRUSES-CURRENT OVERVIEW

Nanotechnology is having a high impact on the development of a novel class of biosensors called nanobiosensors. This technology has utilized some extremely exciting elements for sensing phenomenon improvement. The utilization of nano-materials, nano-rods, nano-particles, nano-tubes have aided rapid, reliable reproducibility and its detection in a much better way. The unique properties of nanobiosensors and its varied applications have influenced biosensing research. Since longtime, nanobiosensors have been utilized worldwide for the diagnosis of diseases co-related with molecular detection of biomarkers. This paper highlights the use of such nanobiosensors for the detection of the virus, infections, fungal pathogens, Human Immunodeficiency Virus (HIV) related diseases such as Cardiovascular diseases (CDVs), Renal Arthritis (RA) through different techniques including electrochemical biosensing, optical biosensing, point of care-diagnostics etc

Multiplexed immunosensors for point-of-care diagnostic applications

Accurate, reliable, and cost-effective immunosensors are clinically important for the early diagnosis and monitoring of progressive diseases, and multiplexed sensing is a promising strategy for the next generation of diagnostics. This strategy allows for the simultaneous detection and quantification of multiple biomarkers with significantly enhanced reproducibility and reliability, whilst requiring smaller sample volumes, fewer materials, and shorter average analysis time for individual biomarkers than individual tests. In this opinionated review, we compare different techniques for the development of multiplexed immunosensors. We review the state-of-the-art approaches in the field of multiplexed immunosensors using electrical, electrochemical, and optical methods. The barriers that prevent translating this sensing strategy into clinics are outlined together with the potential solutions. We also share our vision on how multiplexed immunosensors will continue their evolution in the coming years

Nucleic Acid-based Detection of Bacterial Pathogens Using Integrated Microfluidic Platform Systems

The advent of nucleic acid-based pathogen detection methods offers increased sensitivity and specificity over traditional microbiological techniques, driving the development of portable, integrated biosensors. The miniaturization and automation of integrated detection systems presents a significant advantage for rapid, portable field-based testing. In this review, we highlight current developments and directions in nucleic acid-based micro total analysis systems for the detection of bacterial pathogens. Recent progress in the miniaturization of microfluidic processing steps for cell capture, DNA extraction and purification, polymerase chain reaction, and product detection are detailed. Discussions include strategies and challenges for implementation of an integrated portable platform

Iron chaperones PCBP1 and PCBP2 mediate the metallation of the dinuclear iron enzyme deoxyhypusine hydroxylase

Although cells express hundreds of metalloenzymes, the mechanisms by which apoenzymes receive their metal cofactors are largely unknown. Poly(rC)-binding proteins PCBP1 and PCBP2 are multifunctional adaptor proteins that bind iron and deliver it to ferritin for storage or to prolyl and asparagyl hydroxylases to metallate the mononuclear iron center. Here, we show that PCBP1 and PCBP2 also deliver iron to deoxyhypusine hydroxylase (DOHH), the dinuclear iron enzyme required for hypusine modification of the translation factor eukaryotic initiation factor 5A. Cells depleted of PCBP1 or PCBP2 exhibited loss of DOHH activity and loss of the holo form of the enzyme in cells, particularly when cells were made mildly iron-deficient. Lysates containing PCBP1 and PCBP2 converted apo-DOHH to holo-DOHH in vitro with greater efficiency than lysates lacking PCBP1 or PCBP2. PCBP1 bound to DOHH in iron-treated cells but not in control or iron-deficient cells. Depletion of PCBP1 or PCBP2 had no effect on the cytosolic Fe-S cluster enzyme xanthine oxidase but led to loss of cytosolic aconitase activity. Loss of aconitase activity was not accompanied by gain of RNAbinding activity, a pattern suggesting the incomplete disassembly of the [4Fe-4S] cluster. PCBP depletions had minimal effects on total cellular iron, mitochondrial iron levels, and heme synthesis. Thus, PCBP1 and PCBP2 may serve as iron chaperones to multiple classes of cytosolic nonheme iron enzymes and may have a particular role in restoring metal cofactors that are spontaneously lost in iron deficient cells

Wireless Point-of-Care Platform With Screen-Printed Sensors for Biomarkers Detection

Measurement systems for early and reliable detection of degenerative diseases, such as Alzheimer's disease (AD), are extremely important in clinical diagnosis. Among these, biochemical assays represent a commonly used method to distinguish patients from healthy population thanks to the sensitive recognition of specific biomarkers in biological fluids. In order to overcome actual limitations of these techniques in term of cost, standardization, and sensitivity, this study aimed to realize a low-cost highly sensitive portable point-of-care (PoC) testing system based on screen-printed electrochemical sensors. The development of the platform specifically included both the design of the sensing probe and the electronic circuit devoted to condition and acquires the transduced electric signal. The designed circuit was implemented in a printed circuit board and interfaced to a wireless system based on bluetooth data transmission in order to improve the portability of the proposed solution. Preliminary results were obtained by using controlled concentrations of electrolytic solutions and calibrating the sensors for antibodies and for a well-known protein (i.e., interleukin 8) quantified by anodic stripping voltammetry (ASV). Findings from ASV measurements showed a sensitivity of 38 μA/(ng/ml) with a tested range from 1.25 to 20 ng/ml, with a limit of detection of 2 ng/ml. Further investigation will include the validation of this PoC device by testing the concentration of a specific p53 protein isoform, which was recently identified to early correlate to AD development

Detection of Pathogens Using Microfluidics and Biosensors

Point-of-care devices technology are a promising way towards the recognition of pathogens in early-stage diagnosis, which is critical for the success of inexpensive treatments as opposed to the high costs of managing the disease. The integration of immunoassays with read out circuitry allows the implementation of diagnostic devices for their use by untrained personnel, without compromising reliability. In the following chapter, three different biosensors based on lab-on-a-chip (LoC) and microfluidic technologies were designed, assembled and tested for pathogen diagnosis. The devices allowed the effective detection of the human papilloma virus, Mycobacterium tuberculosis and Chagas parasite in shorter times and with smaller sample volumes than those required by current clinical diagnosis techniques. All devices were benchmarked against commercial techniques in terms of cost and time requirement per test