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

A novel colorimetric biosensor based on non-aggregated Au@Ag core–shell nanoparticles for methamphetamine and cocaine detection

We report a novel colorimetric biosensor based on non-aggregation Au@Ag core-shell nanoparticles to detect methamphetamine and cocaine. The biosensor consisted of a reporter probe (RP) that is a specific single-stranded DNA (ssDNA) sequence coated on Au@Ag nanoparticles, a capture probe (CP) conjugated with magnetic beads, and an illicit drug-binding DNA aptamer (Apt). Au@Ag nanoparticles were synthesized by seed growth and characterized by scanning electron microscope (SEM), high-resolution transmission electron microscopy (HR-TEM), and UV–vis spectra. Methamphetamine (METH) was used as an example to evaluate the feasibility of the biosensor and to optimize the detection conditions. We demonstrated that this sensing platform was able to detect as low as 0.1 nM (14.9 ng L−1) METH with a negligible interference from other common illicit drugs. Various concentrations of METH were spiked into urines, and the biosensor yielded recoveries more than 83.1%. In addition, the biosensor also showed a high sensitivity to detect cocaine. These results demonstrated that our colorimetric sensor holds promise to be implemented as a visual sensing platform to detect multiple illicit drugs in biological samples and environmental matrices

Ultrasensitive Tapered Optical Fiber Refractive Index Glucose Sensor

Refractive index (RI) sensors are of great interest for label-free optical biosensing. A tapered optical fiber (TOF) RI sensor with micron-sized waist diameters can dramatically enhance sensor sensitivity by reducing the mode volume over a long distance. Here, a simple and fast method is used to fabricate extremely sensitive refractive index sensors based on localized surface plasmon resonance (LSPR). Two TOFs (l = 5 mm) with waist diameters of 5 µm and 12 µm demonstrated sensitivity enhancement at λ = 1559 nm for glucose sensing (5–45 wt%) at room temperature. The optical power transmission decreased with increasing glucose concentration due to the interaction of the propagating light in the evanescent field with glucose. The coating of the TOF with gold nanoparticles (AuNPs) as an active layer for glucose sensing generated LSPR through the interaction of the evanescent wave with AuNPs deposited at the tapered waist. The results indicated that the TOF (Ø = 5 µm) exhibited improved sensing performance with a sensitivity of 1265%/RIU compared to the TOF (Ø = 12 µm) at 560%/RIU towards glucose. The AuNPs were characterized using scanning electron microscopy and ultraviolent-visible spectroscopy. The AuNPs-decorated TOF (Ø = 12 µm) demonstrated a high sensitivity of 2032%/RIU toward glucose. The AuNPs- decorated TOF sensor showed a sensitivity enhancement of four times over TOF (Ø = 12 µm) with RI ranging from 1.328 to 1.393. The fabricated TOF enabled ultrasensitive glucose detection with good stability and fast response that may lead to next-generation ultrasensitive biosensors for real-world applications, such as disease diagnosis

Applications of Nanomaterials in Electrogenerated Chemiluminescence Biosensors

Electrogenerated chemiluminescence (also called electrochemiluminescence and abbreviated ECL) involves the generation of species at electrode surfaces that then undergo electron-transfer reactions to form excited states that emit light. ECL biosensor, combining advantages offered by the selectivity of the biological recognition elements and the sensitivity of ECL technique, is a powerful device for ultrasensitive biomolecule detection and quantification. Nanomaterials are of considerable interest in the biosensor field owing to their unique physical and chemical properties, which have led to novel biosensors that have exhibited high sensitivity and stability. Nanomaterials including nanoparticles and nanotubes, prepared from metals, semiconductor, carbon or polymeric species, have been widely investigated for their ability to enhance the efficiencies of ECL biosensors, such as taking as modification electrode materials, or as carrier of ECL labels and ECL-emitting species. Particularly useful application of nanomaterials in ECL biosensors with emphasis on the years 2004-2008 is reviewed. Remarks on application of nanomaterials in ECL biosensors are also surveyed

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

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

Electrochemical and PEC platforms for miRNA and other epigenetic markers of cancer diseases: Recent updates

Abstract Besides playing significant biological roles, microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) constitute emerging and burgeoning cancer biomarkers collectable from human fluids. Electrochemical and photoelectrochemical biosensors offer great potential for their detection. However, the low abundance of such molecules in biological fluids, especially in early-stage cancer patients, makes it highly necessary to employ signal/sample amplification strategies. Among the variety of these strategies reported in the literature, in this review we summarize the recent advancements in the field, giving an account of the different approaches aimed to overcome this main obstacle. To this end, enzyme-, redox probe- and nanomaterial-based signal amplification strategies, as well as sample-amplification-hyphenated-techniques are assessed, by discussing selected examples. The highlighted approaches demonstrate the use of a variety of specific receptors and (photo)electrochemical assay formats, including the rapid development of novel biology-inspired sensing schemes

New trends in aptamer-based electrochemical biosensors

The analytical characteristics of aptamers are comparable with those of antibodies for the development of biosensor technology. However, aptamers offer some crucial advantages over antibodies such as selection capability for a variety of targets, easy synthesis, improved reproducibility and stability, simple modification for immobilization to solid supports and enhanced selectivity. This article reviews aptamer technology as well as aptamer-based assay configurations and goes on to explore reported applications in electrochemical aptasensors

Non-Invasive Breast Cancer Diagnosis through Electrochemical Biosensing at Different Molecular Levels

The rapid and accurate determination of specific circulating biomarkers at different molecular levels with non- or minimally invasive methods constitutes a major challenge to improve the breast cancer outcomes and life quality of patients. In this field, electrochemical biosensors have demonstrated to be promising alternatives against more complex conventional strategies to perform fast, accurate and on-site determination of circulating biomarkers at low concentrations in minimally treated body fluids. In this article, after discussing briefly the relevance and current challenges associated with the determination of breast cancer circulating biomarkers, an updated overview of the electrochemical affinity biosensing strategies emerged in the last 5 years for this purpose is provided highlighting the great potentiality of these methodologies. After critically discussing the most interesting features of the electrochemical strategies reported so far for the single or multiplexed determination of such biomarkers with demonstrated applicability in liquid biopsy analysis, existing challenges still to be addressed and future directions in this field will be pointed out

Graphene Quantum Dot-Based Electrochemical Immunosensors for Biomedical Applications

In the area of biomedicine, research for designing electrochemical sensors has evolved over the past decade, since it is crucial to selectively quantify biomarkers or pathogens in clinical samples for the efficacious diagnosis and/or treatment of various diseases. To fulfil the demand of rapid, specific, economic, and easy detection of such biomolecules in ultralow amounts, numerous nanomaterials have been explored to effectively enhance the sensitivity, selectivity, and reproducibility of immunosensors. Graphene quantum dots (GQDs) have garnered tremendous attention in immunosensor development, owing to their special attributes such as large surface area, excellent biocompatibility, quantum confinement, edge effects, and abundant sites for chemical modification. Besides these distinct features, GQDs acquire peroxidase (POD)-mimicking electro-catalytic activity, and hence, they can replace horseradish peroxidase (HRP)-based systems to conduct facile, quick, and inexpensive label-free immunoassays. The chief motive of this review article is to summarize and focus on the recent advances in GQD-based electrochemical immunosensors for the early and rapid detection of cancer, cardiovascular disorders, and pathogenic diseases. Moreover, the underlying principles of electrochemical immunosensing techniques are also highlighted. These GQD immunosensors are ubiquitous in biomedical diagnosis and conducive for miniaturization, encouraging low-cost disease diagnostics in developing nations using point-of-care testing (POCT) and similar allusive techniques.TU Berlin, Open-Access-Mittel - 201