Recent advances in developing optical and electrochemical sensors for analysis of methamphetamine: A review

Recognition of misused stimulant drugs has always been a hot topic from a medical and judicial perspective. Methamphetamine (MAMP) is an addictive and illegal drug that profoundly affects the central nervous system. Like other illicit drugs, the detection of MAMP in biological and street samples is vital for several organizations such as forensic medicine, anti-drug headquarters and diagnostic clinics. By emerging nanotechnology and exploiting nanomaterials in sensing applications, a great deal of attention has been given to the design of analytical sensors in MAMP tracing. For the first time, this study has briefly reviewed all the optical and electrochemical sensors in MAMP detection from earlier so far. How various receptors with engineering nanomaterials allow developing novel approaches to measure MAMP have been studied. Fundamental concepts related to optical and electrochemical recognition assays in which nanomaterials have been used and relevant MAMP sensing applications have been comprehensively covered. Challenges, opportunities and future outlooks of this field have also been discussed at the end. (C) 2021 Elsevier Ltd. All rights reserved

Nanomaterials for Healthcare Biosensing Applications

In recent years, an increasing number of nanomaterials have been explored for their applications in biomedical diagnostics, making their applications in healthcare biosensing a rapidly evolving field. Nanomaterials introduce versatility to the sensing platforms and may even allow mobility between different detection mechanisms. The prospect of a combination of different nanomaterials allows an exploitation of their synergistic additive and novel properties for sensor development. This paper covers more than 290 research works since 2015, elaborating the diverse roles played by various nanomaterials in the biosensing field. Hence, we provide a comprehensive review of the healthcare sensing applications of nanomaterials, covering carbon allotrope-based, inorganic, and organic nanomaterials. These sensing systems are able to detect a wide variety of clinically relevant molecules, like nucleic acids, viruses, bacteria, cancer antigens, pharmaceuticals and narcotic drugs, toxins, contaminants, as well as entire cells in various sensing media, ranging from buffers to more complex environments such as urine, blood or sputum. Thus, the latest advancements reviewed in this paper hold tremendous potential for the application of nanomaterials in the early screening of diseases and point-of-care testing

Recent Advancements in Bipolar Electrochemical Methods of Analysis

The goal of this review is to provide an overview of the advancements made in the field of bipolar electrochemistry over the past 2 years, with an emphasis on analysis. Bipolar electrodes (BPEs) are versatile, and in electroanalysis, they have been used extensively to screen electrocatalysts(1−4) and to sense biomarkers.(5−10) Their ability to modulate local electric fields lends them to the manipulation of cells and to the enrichment and separation of analytes.(11−17) Finally, by virtue of the polar and often graded profile of the interfacial potential across BPEs, they provide a platform for synthesis of Janus particles, useful as sensors and as microswimmers(18−22) and other materials with compositional gradients.(23,24) BPEs are particularly well-suited to analytical challenges that demand multiplexing or amenability to point-of-need (PON) application because even large arrays of BPEs can be controlled with simple equipment yet yield quantitative information about a system. In this review, we discuss recent progress in reactions that transduce current to a visible signal, sensing mechanisms, bipolar electrochemical cell design, integration of bipolar electrochemistry with spectroscopic techniques, BPEs at the nanoscale, and the application of BPEs to electrokinetics and materials preparation. Throughout the discussion, we identify promising trends, innovative directions, and remaining challenges in the field

Strategies for Miniaturized Biomarker Detection

The aim of this thesis is development and application of different miniaturized strategies for detection of biomarkers. The biomarker PSA (prostate specific antigen), which is prostate cancer specific, has been the main focus of the thesis. The papers present two miniaturized strategies for biomarker detection, developed at the department, an antibody microarray and the ISET platform. The antibody microarray, based on a micro- and nanoporous silicon surface, which increases the sensitivity of the assay, was utilized to quantitatively measure the prostate cancer biomarker PSA. The microarray was also developed to measure the two forms of PSA: total PSA and free PSA, which together gives a better indication of the prostate cancer disease. The second platform for proteomic analysis, the in-house developed platform ISET, which is a sample preparation platform for MALDI mass spectrometry, was first redesigned to be able to handle more viscous samples and larger volumes. Subsequent to the new configuration of the ISET platform, three new applications were developed and published within the framework of this thesis; digestion and detection of the biomarker PSA, protein validation of recombinant protein production, and aptamers as affinity ligand rather than antibody to reduce the background from the affinity probe when performing digestion of the captured protein. The ISET sample preparation was also automated using liquid handling robotics for faster analysis in for example screening procedures. In addition to the microarray, the porous silicon surface was utilized to capture PSA and analyse through the use of reporter mass tags ionized in the mass spectrometry

Developments in nanoparticles for use in biosensors to assess food safety and quality

The following will provide an overview on how advances in nanoparticle technology have contributed towards developing biosensors to screen for safety and quality markers associated with foods. The novel properties of nanoparticles will be described and how such characteristics have been exploited in sensor design will be provided. All the biosensor formats were initially developed for the health care sector to meet the demand for point-of-care diagnostics. As a consequence, research has been directed towards miniaturization thereby reducing the sample volume to nanolitres. However, the needs of the food sector are very different which may ultimately limit commercial application of nanoparticle based nanosensors. © 2014 Elsevier Ltd

Applications of Graphene Quantum Dots in Biomedical Sensors

Due to the proliferative cancer rates, cardiovascular diseases, neurodegenerative disorders, autoimmune diseases and a plethora of infections across the globe, it is essential to introduce strategies that can rapidly and specifically detect the ultralow concentrations of relevant biomarkers, pathogens, toxins and pharmaceuticals in biological matrices. Considering these pathophysiologies, various research works have become necessary to fabricate biosensors for their early diagnosis and treatment, using nanomaterials like quantum dots (QDs). These nanomaterials effectively ameliorate the sensor performance with respect to their reproducibility, selectivity as well as sensitivity. In particular, graphene quantum dots (GQDs), which are ideally graphene fragments of nanometer size, constitute discrete features such as acting as attractive fluorophores and excellent electro-catalysts owing to their photo-stability, water-solubility, biocompatibility, non-toxicity and lucrativeness that make them favorable candidates for a wide range of novel biomedical applications. Herein, we reviewed about 300 biomedical studies reported over the last five years which entail the state of art as well as some pioneering ideas with respect to the prominent role of GQDs, especially in the development of optical, electrochemical and photoelectrochemical biosensors. Additionally, we outline the ideal properties of GQDs, their eclectic methods of synthesis, and the general principle behind several biosensing techniques.DFG, 428780268, Biomimetische Rezeptoren auf NanoMIP-Basis zur Virenerkennung und -entfernung mittels integrierter Ansätz

Point-of-Need DNA Testing for Detection of Foodborne Pathogenic Bacteria

Foodborne pathogenic bacteria present a crucial food safety issue. Conventional diagnostic methods are time-consuming and can be only performed on previously produced food. The advancing field of point-of-need diagnostic devices integrating molecular methods, biosensors, microfluidics, and nanomaterials offers new avenues for swift, low-cost detection of pathogens with high sensitivity and specificity. These analyses and screening of food items can be performed during all phases of production. This review presents major developments achieved in recent years in point-of-need diagnostics in land-based sector and sheds light on current challenges in achieving wider acceptance of portable devices in the food industry. Particular emphasis is placed on methods for testing nucleic acids, protocols for portable nucleic acid extraction and amplification, as well as on the means for low-cost detection and read-out signal amplification

Optical biosensors - Illuminating the path to personalized drug dosing

Optical biosensors are low-cost, sensitive and portable devices that are poised to revolutionize the medical industry. Healthcare monitoring has already been transformed by such devices, with notable recent applications including heart rate monitoring in smartwatches and COVID-19 lateral flow diagnostic test kits. The commercial success and impact of existing optical sensors has galvanized research in expanding its application in numerous disciplines. Drug detection and monitoring seeks to benefit from the fast-approaching wave of optical biosensors, with diverse applications ranging from illicit drug testing, clinical trials, monitoring in advanced drug delivery systems and personalized drug dosing. The latter has the potential to significantly improve patients' lives by minimizing toxicity and maximizing efficacy. To achieve this, the patient's serum drug levels must be frequently measured. Yet, the current method of obtaining such information, namely therapeutic drug monitoring (TDM), is not routinely practiced as it is invasive, expensive, time-consuming and skilled labor-intensive. Certainly, optical sensors possess the capabilities to challenge this convention. This review explores the current state of optical biosensors in personalized dosing with special emphasis on TDM, and provides an appraisal on recent strategies. The strengths and challenges of optical biosensors are critically evaluated, before concluding with perspectives on the future direction of these sensors

Wearable technology for one health: Charting the course of dermal biosensing

Over the last decade, a significant paradigm shift has been observed towards leveraging less invasive biological fluids—such as skin interstitial fluid (ISF), sweat, tears, and saliva—for health monitoring. This evolution seeks to transcend traditional, invasive blood-based methods, offering a more accessible approach to health monitoring for non-specialized personnel. Skin ISF, with its profound resemblance to blood, emerges as a pivotal medium for the real-time, minimally invasive tracking of a broad spectrum of biomarkers, thus becoming an invaluable asset for correlating with blood-based data. Our exploration delves deeply into the development of wearable molecular biosensors, spotlighting dermal sensors for their pivotal roles across both clinical and everyday health monitoring scenarios and underscoring their contributions to the holistic One Health initiative. In bringing forward the myriad challenges that permeate this field, we also project future directions, notably the potential of skin ISF as a promising candidate for continuous health tracking. Moreover, this paper aims to catalyse further exploration and innovation by presenting a curated selection of seminal technological advancements. Amidst the saturated landscape of analytical literature on translational challenges, our approach distinctly seeks to highlight recent developments. In attracting a wider spectrum of research groups to this versatile domain, we endeavour to broaden the collective understanding of its trajectory and potential, mapping the evolution of wearable biosensor technology. This strategy not only illuminates the transformative impact of wearable biosensors in reshaping health diagnostics and personalized medicine but also fosters increased participation and progress within the field. Distinct from recent manuscripts in this domain, our review serves as a distillation of key concepts, elucidating pivotal papers that mark the latest advancements in wearable sensors. Through presenting a curated collection of landmark studies and offering our perspectives on the challenges and forward paths, this paper seeks to guide new entrants in the area. We delineate a division between wearable epidermal and subdermal sensors—focusing on the latter as the future frontier—thereby establishing a unique discourse within the ongoing narrative on wearable sensing technologies

Pharmachk: robust device for counterfeit and substandard medicines screening on developing regions

Thesis (Ph.D.)--Boston UniversityCounterfeit and substandard medicines are a grave public health concern that comprises a $75B black market and claims over 100,000 lives every year. The World Health Organization estimates that 10-50% of medicines in countries around the world are adulterated, and their presence imposes serious financial and economic burdens while also contributing to the rise of drug-resistant pathogens. Although a plethora of technologies are available for field-based quality screening, none reliably quantify active pharmaceutical ingredient (API) content or kinetic release from a dissolving tablet. The United States Pharmacopeia, a global leader in medicines standards for over 150 years, indicates that these quality measures are vitally important yet remain outside of the reach ofexisting screening tools. The current field standard relies on thin layer chromatography to only provide qualitative results that make it difficult to discern between tablets that contain 80% and 100% API. Meanwhile, international standards set the threshold for substandard medicines at 90%. This clear lack of appropriately quantitative and field- ready analytical tools poses a serious problem for national and international policymakers who are plagued with wildly variable information that prevents focused and deliberate action against the spread ofthese medications. This work presents an alternative analytical technique that can specifically and accurately quantify drug API content and kinetic release. PharmaChk provides an orthogonal approach to existing technologies using a portable, inexpensive, and easy-to-use platform. We demonstrate that aptamers can provide a simple and effective way to target a wide range of APis, while maintaining high quantitative precision and accuracy. A microfluidic, flow-through system is employed to obtain valuable drug quality information using a single step procedure. Through our research, we demonstrate the development of the PharmaChk platform from the proof-of-concept stage to beta prototyping and field-testing. By providing a portable, robust, and quantitative approach to medicines testing, PharmaChk can enable the collection of important drug quality information throughout pharmaceutical supply chains and ultimately save the lives of millions that are not afforded safe and essential medicines