Search

Anis Nurashikin Nordin Department of Electrical and Computer Engineering, International Islamic University Malaysia, Kuala Lumpur, Malaysia Abstract: Optofluidic devices have emerged as a promising label-free method for sensitive detection of biological molecules. Its advantages of rapid analysis, high specificity, and low interactions with samples have made it a popular device for biological and chemical analyses. This mini review describes state-of-the-art optofluidic devices based on optical resonators for biosensing. Advanced optical resonator geometries such as microspheres, microrings, and their integration with fluidics have been described. It is predicted that to meet demands of disease diagnostics for multiple clinically relevant samples, sizes of optical resonators will shrink further and geometries that enable multiplexing and integration with signal processing will be the trend of the future. Keywords: optofluidics, optical resonators, microrings, biosensors, microspheres, multiplexed microrings

Harish Kumar, Rani Neelam Electrochemistry Laboratory, Department of Chemistry, Chaudhary Devi Lal University, Sirsa, Haryana, India Abstract: In recent years, food storage environment safety has been a major concern for food and health scientists. There is growing interest in electrochemical biosensors due to their high sensitivity and rapid response. The aim of this review article is to provide details regarding the development of enzyme-based electrochemical biosensors, and their use in the detection of a range of chemical and biological compounds in the food industry. We have focused on the basic principle, generation, classification, and application of electrochemical biosensors for food safety. Keywords: electrochemical biosensor, bioreceptor, transducer, food-borne pathogens

Alphus D Wilson Forest Insect and Disease Research (FIDR), Southern Hardwoods Laboratory, Center for Bottomland Hardwoods Research, Southern Research Station, USDA Forest Service, Stoneville, MS, USA Abstract: Electronic-nose (e-nose) devices are instruments designed to detect and discriminate between precise complex gaseous mixtures of volatile organic compounds derived from specific organic sources, such as clinical test samples from patients, based on electronic aroma signature patterns (distinct digital sensor responses) resulting from the combined outputs of a multisensor array. E-nose tools allow the identification of complex gaseous samples at relatively low costs, making them useful in a diverse range of clinical situations, particularly for assessments of a patients' metabolic (physiological) health and for diagnostic applications. The acquisition and analysis of e-nose clinical "breathprints" or "smellprints", taken from patients' exhaled air, allow for the potential detection of a wide range of human ailments due to abnormal metabolic activities, disorders, and diseases that may be present in the lungs, other organs, and various compartments of the human body. E-nose instruments have shown strong capabilities for detecting inflammatory lung diseases, various types of cancers, patients' exposure to toxins and harmful drugs, organ failures, and many other abnormal human conditions. The increasing trend of medical procedures to move toward the use of noninvasive diagnostic methods, such as breath analysis of complex gases and metabolic biomarkers using e-nose devices, is likely to continue because these methods are quicker, more efficient, and cause less stress, anxiety, and pain to patients. The need for standardization of e-nose analysis methods for use in clinical applications will be resolved with new research, eventually allowing the use of portable e-nose devices in clinical practice to become routine and accepted as the preferred tools of choice by physicians for many clinical tasks. This review provides a brief summary of recent progress in the development of e-nose applications for clinical examinations, general medical practice, and for other branches of medical science and research. Keywords: breath analysis, electronic aroma detection, e-nose, point-of-care diagnostic testing, volatile organic compounds

Kenzo Maehashi,1 Yasuhide Ohno,2 Kazuhiko Matsumoto3 1Institute of Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, 2Institute of Technology and Science, The University of Tokushima, Tokushima, 3The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka, Japan Abstract: Label-free detection of biomolecules has attracted great attention in a lot of life science fields such as genomics, clinical diagnosis, and practical pharmacy. In recent years, for early detection and medical treatment of serious disease, hand-held biosensors for home medical care systems have been intensely developed. In this article we review label-free biosensors based on nanomaterial transistors in which silicon nanowires, carbon nanotubes, and graphene are used as channels. Such nanomaterial-based transistors have high potential for fabrication of label-free biological sensors with high sensitivity. In this review we introduce the detection mechanism of biomolecules using transistors, and show that an electrical double layer in a solution acts as a thin insulator with dielectric constant in transistor-based biosensors. Moreover, we discuss the effect of the electrical double layers in a solution on sensitivity of nanomaterial transistor-based biosensors using the example of label-free electrical detection of biomolecules and fabrication technology of biosensors based on nanomaterial transistors. Keywords: label-free biosensors, Si nanowires, carbon nanotubes, graphene, field-effect transistors, electrical double layers

Gauri M Shukla, Soumyo MukherjiDepartment of Bioscience and Bioengineering, IIT Bombay, Mumbai, Maharashtra, IndiaAbstract: Recent advances in nanotechnology and nanofabrication have helped develop a wide variety of nanostructured platforms for use as nanoplasmonic biosensors. These can either be in solution phase or be confined on a substrate in the form of metallic nanofilms or periodic arrays. Plasmonic properties of these nanostructures depend on the size, shape, position, orientation, etc, and can be altered by interaction between probe and target species on the metal surfaces. This property of nanostructures has been exploited in refractometric nanoplasmonic biosensors, surface-enhanced Raman spectroscopy-based biosensors, plasmon-enhanced fluorescence biosensors, etc. These nanoplasmonic biosensors are employed in diverse areas such as clinical diagnosis, biosecurity, food, and environmental monitoring. Among these, clinical diagnosis has attracted the most research and commercial interest. Nanoplasmonic biosensors can detect disease biomarkers using highly specific and selective biological recognition elements on the nanostructured surfaces. Many excellent reviews exist in this area that trace the developments over the past 3 decades. This review focuses on some of the more recent studies on the detection of various disease biomarkers through nanoplasmonic biosensors. In the process, we have described fabrication techniques and biofunctionalization of such biosensors.Keywords: nanostructures, localized surface plasmon resonance (LSPR), surface-enhanced Raman spectroscopy (SERS)

Julio A Hernández, Mirna García, Dalia Gómez, Joaquín Oseguera Monterrey Institute of Technology and Higher Education, Campus State of Mexico, Atizapan of Zaragoza, State of Mexico, Mexico Abstract: Aluminum-aluminum nitride-aluminum thin films were deposited by radiofrequency reactive magnetron sputtering on silicon wafers (111). A comparison of three different methods of antibody immobilization relevant for surface modification in biosensor development was undertaken. Antibodies against human epidermal growth factor receptor 2 (HER2), a fundamental protein marker in breast cancer diagnostics, were used as a model in protein identification assays. The techniques evaluated were direct (random) immobilization, alginate (ionic) immobilization, and protein G (oriented) immobilization. Standardized detection capabilities were measured by enzyme-linked immunosorbent assay, and revealed substantial outcomes and differences for each technique. Immobilization using protein G was more efficient. Although immobilization using alginate had lower detection sensibility, it may be compared in sensitivity in some cases and is a more affordable technique. Keywords: human epidermal growth factor receptor 2, antibody immobilization, biosensor, sputtering

Ludmila Krejcova,1 Petr Michalek,2 Miguel Merlos Rodrigo,2 Zbynek Heger,2 Sona Krizkova,1 Marketa Vaculovicova,1 David Hynek,1 Vojtech Adam,1 Rene Kizek1 1Central European Institute of Technology, Brno University of Technology, 2Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Brno, Czech Republic Abstract: Since the beginning of the new millennium, viruses have shown huge epidemiological and pandemic potential: severe acute respiratory syndrome (SARS) in 2002, pandemic swine flu in 2009, and last but not least the West African Ebola outbreak in 2014. The occurrence and spread of the new virus in pandemic dimension poses a threat to the health and lives of 7 billion people worldwide. There is a growing urgency for highly sensitive and selective detection techniques, usable for a wide number of applications, including disease diagnosis, pharmaceutical research, agriculture, as well as preventive measures. Nanobiosensors represent a new promising tool for virus detection. This review gives a brief survey of the issue of viral detection, comprising diagnostics of target structure of viruses such as nucleic acids or proteins. This review covers different detection principles, methods of fabrication, and applications of virus biosensors. Keywords: nanoparticle, nanomaterial, diagnostics, immunosensors, hybridization&nbsp

Chetna Dhand,1 Neeraj Dwivedi,2 Sachin Mishra,3 Pratima R Solanki,4 Venkatesh Mayandi,1 Roger W Beuerman,1,5 Seeram Ramakrishna,6 Rajamani Lakshminarayanan,1,5 Bansi D Malhotra7 1Anti-Infectives Research Group, Singapore Eye Research Institute, Singapore; 2Department of Electrical and Computer Engineering, National University of Singapore, Singapore; 3School of Engineering, Gautam Buddha University, Greater Noida, India; 4Special Centre for Nanoscience, Jawaharlal Nehru University, New Delhi, India; 5Duke-NUS SRP Neuroscience and Behavioral Disorders, Singapore; 6Center for Nanofibers and Nanotechnology, Department of Mechanical Engineering, National University of Singapore, Singapore; 7Department of Biotechnology, Delhi Technological University, Delhi, India Abstract: Biosensors are the subject of an immensely growing field of research owing to their broad range of applications in medicines, pharmacy, environmental monitoring, food and process control, defense and security, and principally in diagnostics. Diverse materials have been investigated for the advancement of biosensors in terms of their miniaturization, sophistication, cost, biosensing features, ie, detection limit, sensitivity, stability, selectivity, etc. Polyaniline (PANI) is one of the most interesting conductive polymers for biosensor design in view of its excellent electrochemical properties (polyelectrocatalytic characteristics, reversible redox behavior, and electrochemical tunability), straightforward processability, long-term environmental stability, and functionality-rich chemical structure. In this review, an attempt is made to compile almost all the existent literature on PANI-based biosensors in terms of enzymatic biosensors (for H2O2, glucose, cholesterol, phenol/polyphenol/catecholamine detection), genosensors (DNA sensing), and immunosensors from 2006 to 2015. Furthermore, reports available on the biosensing of urea, uric acid, creatinine, pesticides, amino acids, and other clinically significant analytes are also assembled to provide a comprehensive overview on PANI-based biosensors. Keywords: polyaniline, biosensor, direct electron transfer, mediator-free biosensor, conducting polymer, nucleic acid biosensor, immunosensor

Raquel Vinhas,1,2* Milton Cordeiro,1,3* Fábio Ferreira Carlos,1,4 Soraia Mendo,1,2 Alexandra R Fernandes,2 Sara Figueiredo,1 Pedro V Baptista1 1Nanomedicine@FCT, CIGMH (Centro de Investigação em Genética Molecular Humana), UCIBIO, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus da Caparica, Caparica, Portugal; 2UCIBIO (Unidade de Ciências Biomoleculares Aplicadas), Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus da Caparica, Caparica, Portugal; 3REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus da Caparica, Caparica, Portugal; 4STABVIDA, Investigação e Serviços em Ciências Biológicas, Lda, Madan Parque, Caparica, Portugal *These authors contributed equally to this work Abstract: Nanotheranostics takes advantage of nanotechnology-based systems in order to diagnose and treat a specific disease. This approach is particularly relevant for personalized medicine, allowing the detection of a disease at an early stage, to direct a suitable therapy toward the target tissue based on the molecular profile of the altered phenotype, subsequently facilitating disease monitoring and following treatment. A tailored strategy also enables to reduce the off-target effects associated with universal treatments and improve the safety profile of a given treatment. The unique optical properties of gold nanoparticles, their ease of surface modification, and high surface-to-volume ratio have made them central players in this area. By combining imaging, targeting, and therapeutic agents in a single vehicle, these nanoconjugates are (ought to be) an important tool in the clinics. In this review, the multifunctionality of gold nanoparticles as theranostics agents will be highlighted, as well as the requirements before the translation of these nanoplatforms into routine clinical practice. Keywords: nanotheranostics, nanomaterials, gold nanoparticle, theranostics, cancer, nanomedicine

Zeynep Altintas, Ibtisam E Tothill Biomedical Engineering, Cranfield University, Cranfield, UK Abstract: Over the last decade, an increasing number of researchers have focused on developing rapid techniques based on biosensor technology for the detection of various human health-related conditions. Cardiovascular disease, cancer, diabetes, and infectious diseases are at the top of these investigations. Huge advances have taken place in a wide range of disciplines, with improved sensitivity, specificity, and reproducibility of the designed methodologies. Advances in other scientific disciplines, including genetics, chemical and microelectronic engineering, computational sciences, and medicine have also impacted on the developments taking place in the diagnostics field. As a result of these developments, more stable, rapid, and reliable sensing platforms have been successfully constructed for specific and ultrasensitive biomarker-based disease diagnostics. These achievements were also a result of improving sensor production quality, developing appropriate surface chemistries, selection of high affinity ligands for target biomarkers, and using nanomaterials such as carbon nanotubes, magnetic/gold nanoparticles, or quantum dots for signal amplification. Moreover, use of bioinformatics tools, combined with proteomics and genomics technologies and metabolomics, has significantly improved the knowledge and discovery of new biomarkers that can be used for early detection. Due to these significant outputs, coupled with advances in miniaturization and nanotechnology, the demand for development and production of sensor systems, including optical, piezoelectric/acoustic, electrochemical, and colorimetric, has gradually increased during the last decade. Moreover, not only protein and gene markers, but also secondary metabolites and cell signaling pathway molecules can be used for disease detection. To date, diagnostic tests for the early detection of cancer biomarkers are available on the market, and these provide noninvasive/minimally invasive tests that can play a crucial role both in successful treatment and patient survival. This paper reviews disease biomarkers, post-genomic technology, and use of molecular biosensors for early detection of cancer.Keywords: cancer, biomarker discovery, post-genomic technology, molecular biosensors, disease diagnostics

Shalini Prasad Department of Bioengineering, University of Texas, Dallas, TX, USA Abstract: Nanotechnology is having a profound impact on the development of a new class of biosensors known as nanobiosensors. Nanobiosensors commonly comprise a biological recognition molecule immobilized onto the surface of a signal transducer. The reaction between the biorecognition molecule and the analyte is a heterogeneous reaction and therefore the design of the biosensing interface is important in determining the performance of the nanobiosensor. Nanobiosensors are being widely used for molecular detection of biomarkers associated with diagnosis of disease. The application of new nanomaterials in biosensing has influenced biosensing research. The use of high surface area nanomaterials has been important in producing nanobiosensors with greater sensitivity and shorter response times. This review summarizes the advances in disease diagnostics, primarily through the detection of molecular biomarkers, such as proteins and nucleic acids mediated by use of nanobiosensors. Keywords: nanomaterial, biosensors, disease diagnosis, biomimetic, macromolecular crowding, performance metrics

Wonhee Lee1,2, Jinyoung Lee1,2, Joonyoung Koh1,21Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea; 2KAIST Institute for the Nanocentury, Daejeon, Republic of KoreaAbstract: Calorimetry is the science of measuring heat. For more than 200 years now, calorimetry has advanced and various types of calorimeters have been developed for diverse applications. The development of microfabrication and microfluidics led to the advent of chip calorimeters, miniaturized calorimeters built and integrated as chips. Chip calorimeters, as label-free biosensors, have many advantages due to their small sample volume and high-throughput capability. In this review, techniques for realizing chip calorimeters are discussed in terms of their major functional components: insulation, fluid handling, and thermometry. Recent trends in the development of chip calorimeters are also discussed, along with several application areas. New fabrication techniques can provide higher sensitivity and easier, more reliable sample handling for chip calorimeters, which would enable new application areas, such as the study of single cell metabolism.Keywords: chip calorimeter, microfluidic biosensor, thermal sensor

Min Koo, So Young Park, Keon Jae LeeDepartment of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Yuseong-gu, Daejeon, Republic of KoreaAbstract: The use of light-emitting diodes (LEDs) as therapeutic tools has been actively studied over the past few decades due to their advantages of high safety, low cost, excellent portability, and wide bandwidth. In addition, their application in biomedical fields has been expanded to such areas as nerve stimulation, photodynamic therapy, and LED-based biosensors, and LED lights are thus receiving attention as alternatives to conventional biomedical light sources such as lasers. Recently, several developments in the area of flexible inorganic LEDs along with advanced nanoelectronic technologies have pointed toward the possibility of new innovative biomethodologies in the near future. In this paper, we review the salient features of high-performance biointegrated LED applications, together with future challenges for the realization of implantable, flexible biointegrated electronic devices.Keywords: flexible, inorganic, biointegrated, light-emitting diodes, nerve stimulation, photodynamic therapy, biosensor

Chulhee Choi1,21Department of Bio and Brain Engineering, 2Graduate School of Medical Science and Engineering, 3KI for the BioCentury 4Optical Bioimaging Center, KAIST, Daejeon, Republic of KoreaAbstract: Advances in nanotechnology have led to the development of nanoscale biosensors that have exquisite sensitivity and versatility. The biomedical application of nanobiosensors is wide; moreover, the future impact of nanobiosensor systems for point-of-care diagnostics will be unmatched. The ultimate goal of nanobiosensors is to detect any biochemical and biophysical signal associated with a specific disease at the level of a single molecule or cell. This technology will revolutionize conventional medical practices by enabling early diagnosis of chronic debilitating diseases, ultrasensitive detection of pathogens, and long-term monitoring of patients using biocompatible integrated medical instrumentation. In the present commentary, current state-of-the art principles of nanobiosensor systems and integration into lab-on-a-chip devices are discussed along with future perspectives.Keywords: nanotechnology, biosensor, diagnostics, point-of-care, lab-on-a-chip, microfluidics