Biosensors for cardiac biomarkers detection: a review

The cardiovascular disease (CVD) is considered as a major threat to global health. Therefore, there is a growing demand for a range of portable, rapid and low cost biosensing devices for the detection of CVD. Biosensors can play an important role in the early diagnosis of CVD without having to rely on hospital visits where expensive and time-consuming laboratory tests are recommended. Over the last decade, many biosensors have been developed to detect a wide range of cardiac marker to reduce the costs for healthcare. One of the major challenges is to find a way of predicting the risk that an individual can suffer from CVD. There has been considerable interest in finding diagnostic and prognostic biomarkers that can be detected in blood and predict CVD risk. Of these, C-reactive protein (CRP) is the best known biomarker followed by cardiac troponin I or T (cTnI/T), myoglobin, lipoprotein-associated phospholipase A(2), interlukin-6 (IL-6), interlukin-1 (IL-1), low-density lipoprotein (LDL), myeloperoxidase (MPO) and tumor necrosis factor alpha (TNF-α) has been used to predict cardiovascular events. This review provides an overview of the available biosensor platforms for the detection of various CVD markers and considerations of future prospects for the technology are addressed

State-of-the-Art of (Bio)Chemical Sensor Developments in Analytical Spanish Groups

(Bio)chemical sensors are one of the most exciting fields in analytical chemistry today. The development of these analytical devices simplifies and miniaturizes the whole analytical process. Although the initial expectation of the massive incorporation of sensors in routine analytical work has been truncated to some extent, in many other cases analytical methods based on sensor technology have solved important analytical problems. Many research groups are working in this field world-wide, reporting interesting results so far. Modestly, Spanish researchers have contributed to these recent developments. In this review, we summarize the more representative achievements carried out for these groups. They cover a wide variety of sensors, including optical, electrochemical, piezoelectric or electro-mechanical devices, used for laboratory or field analyses. The capabilities to be used in different applied areas are also critically discussed

Gold Nanoparticles: Promising Nanomaterials for the Diagnosis of Cancer and HIV/AIDS

Gold nanoparticles (AuNPs) are currently playing a significant role for human welfare in the field of clinical diagnosis as well as several biomedical applications. More and more research shows that AuNPs-based technologies are becoming promising approaches in cancer research and AIDS treatment. In this paper, we have focused mainly on the exploitation of unique and characteristic properties of AuNPs such as surface plasmon resonance (SPR), surface enhance Raman scattering (SERS), magnetic properties (MRI), and fluorescence behavior shown upon conjugation with biological and biocompatible ligands. These properties find wide prevalence in biodiagnostics like plasmon-based labeling and imaging, enzyme-linked immunosorbant assay (ELISA), and electrochemical-based methods that can pave the way for developing novel techniques towards diagnosis and therapy of cancer and human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS)

Advanced systems for the rapid detection of anthelmintic drugs in food

Several surface plasmon resonance (SPR) biosensor assays were developed and validated for the detection of anthelmintic veterinary drugs in liver tissue and milk using a QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) extraction procedure. The first screening assay was developed to detect 11 benzimidazole carbamates in milk and liver. In bovine milk the assay showed a limit of detection (LOD) of 2.7 μg kg-1 and a detection capability (CCβ) of 5 μg kg-1. Analyte recovery was in the range 81 to 116% and the assay was found to be fit for purpose when its performance was compared to UPLC-MS/MS analyses of milk from cows treated with benzimidazole products. In bovine liver the LOD (32 μg kg-1) and the CCβ (50 μg kg-1) were determined and the analyte recovery was in the range 77-132%. All non-compliant samples were identified when the assay performance was tested by analysing liver from animals treated with benzimidazole drugs and comparing the results with a UPLC-MS/MS confirmatory method. A screening assay was developed for four amino-benzimidazoles in liver. The LOD (41 μg kg-1) and the CCβ (75 μg kg-1) were determined and the analyte recovery was in the range 103-116%. A screening assay for thiabendazole and 5-hydroxy-thiabendazole in ovine liver tissue using a novel recombinant antibody fragment (Fab) was developed. The LOD (12.3 μg kg-1), the CCβ (20 μg kg-1) and analyte recovery (86-107%) satisfied the criteria required for thiabendazole screening in liver tissue. A biosensor to detect triclabendazole residues in liver tissue was developed through the immobilization of amino-triclabendazole via a glutaraldehyde homo-bifunctional crosslinker. Several experiments were required to reduce non-specific binding in this assay. An LOD of 105 μg kg-1 was determined which was close to the maximum residue limit (MRL) in liver matrix (100 μg kg-1).A biochip array was developed and validated to screen orange juice for fungicide and pesticide residues. The LOD for carbendazim (20 μg kg-1), 2-aminobenzimidazole (4.0 μg kg-1), thiabendazole (4.2 μg kg-1) and ivermectin (10.2 μg kg-1) residues were determined. The CCβ for carbendazim (50 μg kg-1), 2-aminobenzimidazole (10 μg kg- 1), thiabendazole (10 μg kg-1) and ivermectin (20 μg kg-1) residues were sufficient for the analysis of orange juice. When orange juice from retail outlets in the greater Dublin area (n = 15) Two samples contained thiabendazole residues above the CCβ (260 and 181 μg kg-1) however these concentrations were below the maximum residue limit

From Molecular Blocks To Bioanalytical Assays: Combining Lanthanide Luminescence and Bioaffinity Binders for Protein Detection

Measuring protein biomarkers from sample matrix, such as plasma, is one of the basic tasks in clinical diagnostics. Bioanalytical assays used for the measuring should be able to measure proteins with high sensitivity and specificity. Furthermore, multiplexing capability would also be advantageous. To ensure the utility of the diagnostic test in point-of-care setting, additional requirements such as short turn-around times, ease-ofuse and low costs need to be met. On the other hand, enhancement of assay sensitivity could enable exploiting novel biomarkers, which are present in very low concentrations and which the current immunoassays are unable to measure. Furthermore, highly sensitive assays could enable the use of minimally invasive sampling. In the development of high-sensitivity assays the label technology and affinity binders are in pivotal role. Additionally, innovative assay designs contribute to the obtained sensitivity and other characteristics of the assay as well as its applicability. The aim of this thesis was to study the impact of assay components on the performance of both homogeneous and heterogeneous assays. Applicability of two different lanthanide-based label technologies, upconverting nanoparticles and switchable lanthanide luminescence, to protein detection was explored. Moreover, the potential of recombinant antibodies and aptamers as alternative affinity binders were evaluated. Additionally, alternative conjugation chemistries for production of the labeled binders were studied. Different assay concepts were also evaluated with respect to their applicability to point-of-care testing, which requires simple yet sensitive methods. The applicability of upconverting nanoparticles to the simultaneous quantitative measurement of multiple analytes using imaging-based detection was demonstrated. Additionally, the required instrumentation was relatively simple and inexpensive compared to other luminescent lanthanide-based labels requiring time-resolved measurement. The developed homogeneous assays exploiting switchable lanthanide luminescence were rapid and simple to perform and thus applicable even to point-ofcare testing. The sensitivities of the homogeneous assays were in the picomolar range, which are still inadequate for some analytes, such as cardiac troponins, requiring ultralow limits of detection. For most analytes, however, the obtained limits of detection were sufficient. The use of recombinant antibody fragments and aptamers as binders allowed site-specific and controlled covalent conjugation to construct labeled binders reproducibly either by using chemical modification or recombinant technology. Luminescent lanthanide labels were shown to be widely applicable for protein detection in various assay setups and to contribute assay sensitivity.Proteiinien mittaaminen biologisesta näytteestä, kuten plasmasta, on kliinisen diagnostiikan perustehtäviä. Kliinisessä diagnostiikassa käytettävien bioanalyyttisten määritysten tulisi olla herkkiä ja tarkkoja, jotta ne voivat mitata proteiineja näytteestä luotettavasti. Lisäksi olisi hyödyllistä pystyä mittaamaan samasta näytteestä monta analyyttiä yhtäaikaisesti. Vieritestaukseen tarkoitettujen testien tulisi edellä mainittujen ominaisuuksien ohella olla nopeita, helppokäyttöisiä ja edullisia. Toisaalta nykyistä merkittävästi herkempien määritysten kehittäminen mahdollistaisi uusien, hyvin pieninä pitoisuuksina esiintyvien biomerkkiaineiden käytön diagnostiikassa. Erittäin herkät määritykset voisivat myös mahdollistaa helposti saatavilla olevien näytemateriaalien käytön. Määrityksen herkkyyteen ja muihin ominaisuuksiin vaikuttavia tekijöitä ovat käytetty leimateknologia sekä sitojamolekyylit. Lisäksi määrityskonseptin valinnalla voidaan vaikuttaa testin suorituskykyyn ja sen soveltuvuuteen esimerkiksi vieritestausolosuhteisiin. Tässä väitöskirjatyössä tutkittiin kahden luminoivan lantanidileimateknologian soveltuvuutta proteiinien mittaamiseen. Yhdessä osatyössä tutkittiin upkonvertoivien eli käänteisviritteisten luminoivien nanopartikkelien käyttökelpoisuutta monianalyyttimäärityksiin ja kolmessa osatyössä kehitettiin nopeita erotusvapaita määrityksiä mallianalyyteille hyödyntäen kytkeytyvää lantanidiluminesenssia. Osatöissä selvitettiin myös rekombinanttisten vasta-ainefragmenttien ja aptameerien soveltuvuutta proteiinipitoisuuksien mittaamiseen. tutkittiin erilaisia konjugointitapoja leiman ja sitojamolekyylin yhdistämiseksi. Lisäksi arvioitiin eri määritystapojen soveltuvuutta vieritestaussovelluksiin. Väitöskirjatyössä osoitettiin, että käänteisviritteisiä nanopartikkeleita voidaan hyödyntää usean analyytin yhtäaikaiseen mittaamiseen käyttämällä kuvantavaa mittaustapaa. Tällöin voidaan käyttää yksinkertaisempaa laitteistoa, sillä toisin kuin muut luminoivat lantanidileimat, käänteisviritteiset nanopartikkelit eivät edellytä aikaerotteista mittaustapaa. Kehitetyt erotusvapaat kytkeytyvää lantanidiluminesenssia hyödyntävät määritykset olivat nopeita ja yksinkertaisia suorittaa, ja siten soveltuvia jopa vieritesteihin. Erotusvapaiden määritysten havaintorajat olivat pikomolaarisella alueella, mikä ei ole riittävän herkkä kaikille analyyteille kuten esimerkiksi sydänspesifisille troponiineille, joiden mittaamiseen vaaditaan erittäin herkkiä testejä. Vasta-ainefragmenttien ja oligonukleotidipohjaisten aptameerien käyttö mahdollisti paikkaspesifisen ja kontrolloidun leima-sitojamolekyyli-konjugaatin muodostamisen joko kemiallisesti tai rekombinanttiteknologiaa käyttäen. Käänteisviritteisten luminoivien nanopartikkelien ja kytkeytyvien lantanidileimojen osoitettiin soveltuvan proteiinien detektioon monenlaisissa määrityskonsepteissa.Siirretty Doriast

Development of Immunoassay Using Graphene and Microfluidic Platforms.

Protein, as one of the most important functional biomolecules in the human body, plays a significant role in physiological responses and molecular diagnostics. Detecting the existence of proteins, quantifying concentration, and identifying protein types are therefore important techniques in many fields. Immunoassays are one of the major techniques relied on for protein detection. Immunoassays have been broadly applied in disease diagnosis, pharmaceutical development, food science, and environmental protection. The first part of this dissertation describes studies aimed at developing chemical vapor deposition (CVD) graphene as a large size protein biosensing platform. To utilize graphene as a biosensing platform, techniques to immobilize proteins on graphene are critical. In this dissertation work, carboxyl functional groups (-COOH) were created by graphene functionalization, and the functionalized graphene was characterized using Raman spectroscopy, X-ray photo spectroscopy (XPS), and fluorescence microscopy. The approach developed here provides information about protein coupling density and uniformity on large scale graphene (> cm2). The second and the third parts of the thesis describe the application of a microfluidic technique to two widely used protein detection methods – immunoblotting and dot blotting. The microfluidic systems were designed and fabricated to be easily interfaced with a common type of protein blotting membrane called polyvinylidene fluoride (PVDF) membrane. The microfluidic device was specifically applied to the antibody incubation step, which reduces antibody consumption and therefore also significantly reduces the cost of the assay. In microfluidic immunoblotting, an approach to activate the PVDF membrane to increase its protein binding capacity was developed. This was achieved by adding a surfactant Tween-20 to the antibody solution. The concentration of Tween-20 was optimized so that only the portion of the membrane within the channel region was activated. The system has been shown to be able to profile inflammatory signaling pathways. In microfluidic dot blotting, the influence of substrate hydrophobicity and protein concentrations on device design constraints were studied. Inflammatory cytokine detection using the developed microfluidic dot blotting system was determined. Altogether these experiments demonstrate that applying microfluidic techniques to protein immunoblotting and dot blotting improves detection efficiency, and reduces cost by utilizing less antibodies.PhDBiomedical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/113501/1/huaining_1.pd

Phage-based biosensors for detection of microbes and biomarkers

The detection of microbial species and communities has always been an area of great importance. Rapid methods for microbial detection are especially important in the medicine, pharmacological, and food industry. The lack of rapid and cost-effective detection methods creates a challenge to control possible epidemics. New pathogenic microbes can cause a worldwide outbreak of diseases, pandemics. The majority of currently used detection methods for pathogens have low sensitivity and specificity. Human microbiota has been demanding and mostly unexplored area before modern high-throughput methods were established. These methods have elucidated a lot of connections between different diseases and composition changes of intestinal microbiota. However, sequencing a large number of samples takes a great deal of time, work and it requires centralized facilities. For microbiota, there are no actual comprehensive and rapid sensors. Biosensors have a great potential to respond to the challenges of microbial detection. The small physical size of the equipment, ease of use and operability outside centralized hospitals are appealing characteristics of this emerging class of diagnostic devices In this thesis, the applicability of newly developed rapid biosensors were evaluated as a tool for the detection of urinary tract infection and biomarkers. The studied methods are not based on traditional immunoassay detection technology, which usually relies on detecting a single antigen from the sample. Instead, a sensitive long lifetime luminescent europium label was used with different modulating probes to nonspecifically interact with simulated samples, but also with hospital samples. Chemical probes, or phages as biological probes, were used successfully to provide multiparameter luminescence data —a fingerprint from each sample. Phage-based methods were designed to meet the challenges of rapid detection of a single bacterial species. The second phage-based study was based on lysogenic phages and tested with hospital samples the assay time was reduced. The proof-of-principle method showed sensitivity and specificity at the 90% mark when compared to the standard culture method. The method was further developed and applied to detect specific biomarkers in a controlled chemical environment and finally to classify lethal prostate cancer against non-lethal ones from urine samples. The assay demonstrated a statistically significant difference between the two groups (pBakteriofageihin perustuvat biosensorit mikrobien ja biomarkkereiden havaitsemisessa Lääketieteessä, lääkeaineiden puhtaassa valmistuksessa ja elintarviketeollisuudessa mikrobien nopea havaitseminen on ensisijaisen tärkeää. Nopeille ja edullisille havaitsemismenetelmille on tarvetta varsinkin epidemioiden hallitsemisessa. Uudet patogeeniset mikrobit voivat aiheuttaa pandemioita, jotka alkuvaiheessa etenevät hyvin nopeasti maanosasta toiseen. Tämän päivän havaitsemismenetelmillä on yleisesti haasteita herkkyydessä ja spesifisyydessä. Ihmisen mikrobiota on ollut pitkään haastava ja tutkimaton alue. Tämä johtuu yksinkertaisesti siitä, ettei tähän tutkimusalueeseen ollut riittäviä tutkimusmenetemiä. Nämä nykyaikaiset menetelmät ovat selventäneet paljon yhteyksiä eri sairauksien ja suolen mikrobiotan koostumuksen muutosten välillä. Koko mikrobiotan testaukseen ei ole käytännössä todellisia pikatestijärjestelmiä. Biosensoreilla on mahdollista vastata mikrobien havaitsemisen asettamiin haasteisiin. Pieni koko, helppokäyttöisyys ja käytettävyys kenttäolosuhteissa ovat houkuttelevia tekijöitä orastavalle diagnostiikkalaitteiden luokalle. Tässä väitöskirjassa arvioitiin erilaisten nopeiden biosensorien soveltuvuutta mikrobien ja biomarkkerien havaitsemisessa. Työssä tutkitut menetelmät eivät perustuneet perinteisiin immunomääritystekniikoihin, jotka perustuvat yleensä yksittäisen antigeenin havaitsemiseen näytteestä. Tämän sijasta käytettiin näytteen kemialliselle ympäristölle herkkää europium-leimaa, jota käytettiin ei-spesifisesti vuorovaikutuksessa sekä simuloidun näytteen että potilasnäytteiden kanssa. Bakteriofagit toimivat biologisina koettimina ja tuottivat moneen eri parametriin perustuvaa luminesenssidataa -sormenjäljen jokaisesta yksittäisestä näytteestä. Bakteriofageihin perustuvat menetelmät kehitettiin ensin yksittäisten bakteerilajien havaitsemiseen ensin simuloiduissa olosuhteissa ja tämä jälkeen potilasnäytteistä. Menetelmää sovellettiin pidemmälle tunnistamaan spesifisistä biomarkkeria säädellyssä kemiallisessa ympäristössä. Lopulta menetelmää käytettiin luokittelemaan tappavat eturauhassyöpänäytteet ei-tappavista näytteistä. Luokittelutestin avulla havainnollistettiin tilastollisesti merkittävä ero näiden kahden näytetyypin välillä (p <0.0014). Yhteenvetona nämä havainnot osoittavat sen, että lantanidi-leimaan ja bakteriofaageihin perustuvaa menetelmää voidaan käyttää spesifisesti biomarkkerin, tai yksittäisen bakteerilajin havaitsemisee

Micro and nano technology platforms: From cell viability monitoring to FET based biosensing

Nanotechnology is a multidisciplinary field that combines science and engineering to design, synthesize, characterize and explore applications for materials and devices whose smallest functional organization in at least one dimension is on the nanometer scale. Nanotechnology is undergoing an explosive development and the extent of potential application is vast and widely diverse. In the field of human health care, nanotechnology is helping to develop novel materials and structures, which have made it possible to miniaturize many of the tools used in conventional assays. Smart biochips constructed out of these novel materials and structures are now capable of performing limited in vitro diagnostic tests involved in immunoassays. In this work, we report two devices that make use of micro scale and/or nano scale structures to contribute to the ever-expanding use of biochips in human health care. The first device is a Patch-Clamp microchip that is capable of monitoring cell viability in real-time. It is critical to monitor the health of cells in biological life science and medical research. Researchers must know if a new drug is capable of killing cancer cells or in other cases to determine the toxic effects of a drug or a pesticide on healthy cells. Conventional cell viability monitoring techniques that use flow cytometer or fluorescent dyes in conjunction with fluorescence microscope are time consuming and require sample labeling. Alternatively, we have designed a patch-clamp microchip, which allows one to measure the ion-channel currents in real-time. This microchip provides a faster and label-free platform to monitor the health of the cell. Simultaneously, viability tests were performed on four different types of cancer cells (MB231, MB231-BR-vector, MB231-BR-HER 2, and MB231-BR) using the conventional fluorescent dye technique and using the patch-clamp microchip technique. For the patch-clamp technique, the seal resistance of the device decreased from ∼22 MΩ, (living cell) to ∼4 MΩ (dead cell) over a period of 120 minutes. Comparing the seal resistance to the intensity of the fluorescence images over the 120 minute period confirms a correlation between the health of the cell and the ion-channel current, validating our claim that the patch-clamp microchip can be used as an alternate technical platform to the conventional techniques that use fluorescent dyes or a flow cytometer. The second device is a Field-Effect Transistor (FET) based biosensor used for the detection of biomolecules. The conventional technique, ELISA, is still the gold standard for immunoassays. Most of the modern biosensors have exploited the semi conductive nature of CNT to design a label-free FET based immunosensor (biosensor that exclusively monitors the antibody-antigen interaction). Even though biosensors made out of a single CNT are ideally capable of detecting a single molecule, the fabrication of such devices is challenging. To avoid the fabrication complexity involved with a single CNT based immunosensor, we have developed an FET based biosensor, in which the channel is made out of Carbon Nanotube Thin Film (CNTF). The CNTF channel between the source and drain electrodes is assembled using electrostatic layer-by-layer (LBL) self-assembly. The bio-affinity interaction between Protein A and rabbit IgG is used to model the antibody-antigen interaction, and our initial results show the device is capable of detecting IgG concentrations as low as 1 pg/mL

New photo-luminescent inorganic materials: high-tec application in chemical sensing and labeling

This thesis describes the potential of various kinds of luminescent nanoparticles with respect to chemical sensing and biosensing. First, fluorescent silica nanoparticles (SiNPs) were prepared by covalent attachment of fluorophores to the amino-modified surface of SiNPs with a typical diameter of 15 nm. The SiNPs were used in novel kinds of Förster resonance energy transfer (FRET)-based affinity assays at the interface between nanoparticle and sample solution. Various labels were employed to obtain a complete set of colored SiNPs, with excitation maxima ranging from 337 to 659 nm and emission maxima ranging from 436 nm to the near infrared (710 nm). The nanoparticles were characterized in terms of size and composition using transmission electron microscopy, thermogravimetry, elemental analysis, and dynamic light scattering. The surface of the fluorescent SiNPs was biotinylated, and binding of labeled avidin to the surface was studied via FRET in two model cases. Secondly, the upconverting luminescent nanoparticles (UCLNPs) consist of hexagonal NaYF4 nanocrystals doped with trivalent rare earth ions were synthesized by both the oleic acid (solvothermal) method and the ethylenediaminetetraacetic acid (coprecipitation) method. The nanoparticles were codoped using Yb3+ as the sensitizer ion, Er3+, Tm3+, or Ho3+ respectively as the emitting activator ions. An affinity system was demonstrated based on the interaction of two types of nanoparticles. The first type consists of UCLNPs of the type NaYF4:Yb,Er absorbing light in the infrared and showing green luminescence at 521 and 543 nm and red luminescence at 657 nm. The second type consists of gold nanoparticles (Au-NPs) with a size of about 50 nm, which absorb the green luminescence of the UCLNPs, but do not influence their red luminescence. A model system for a self referenced affinity system were established by labeling the UCLNPs with avidin and the AuNPs with biotin. In the presence of avidin-modified UCLNPs, the biotinylated Au-NPs can be detected in the range from 12 to 250 µg•mL-1 by rationing the intensity of the red (analyte-independent) emission band to that of the green (analyte-dependent) emission band. All nanoparticles were characterized in terms of size and composition using transmission electron microscopy, thermo-gravimetry, and FTIR spectroscopy. Thirdly, different types of nanoparticles (made from silica, polystyrene and UCLNPs) carrying longwave absorbing and emitting fluorescent labels were prepared by conjugating reactive dyes to the surface of amino-modified particles. The dyes have a reactive chloro group capable of reacting with amino groups and thereby undergoing a change in color, typically from green to blue (the so-called chameleon effect). The latter show the effect of upconversion in that near-infrared laser light is converted into visible luminescence. They also show the unusual property of displaying dual emission, depending on whether their luminescence is photoexcited with visible light or near-infrared light. The amino groups on the surface of nanoparticles were detected via the chameleon effect of the applied amino-reactive dyes. Fourth, the quenching effect of heavy metal ions and halide ions on the luminescence of UCLNPs in aqueous solution was studied. The effect was investigated for the ions Cu(II), Hg(II), Pb(II), Cd(II), Co(II), Ag(I), Fe(III), Zn(II), bromide and iodide, and was found to be particularly strong for Hg(II). Stern-Volmer plots were virtually linear up to 10 – 25 mM concentrations of the quencher, but deviate from linearity at higher quencher concentrations where static quenching caused an additional effect. The UCLNPs display two main emission bands (blue, green, red or near-infrared), and the quenching efficiencies for these found to be different. The effect seems to be generally associated with UCLNPs because it was observed for all particles doped with trivalent lanthanide ions including Yb(III), Er(III), Ho(III), and Tm(III)

Development of Nanostructured Glucose Biosensor

With the development of nanotechnology and nanomaterials, biosensors incorporated with novel nanomaterials and nanostructures have shown significant potential in point-of-care medical devices because of their rapid interaction with target analytes and their miniaturized systems. Nanomaterials and nanostructures with special chemical, physical and biological characteristics are able to enhance biosensors’ performance in terms of sensitivity and selectivity. Therefore, my study focused on development of special nanostructures used for advanced glucose biosensor. Monitoring of blood glucose level is essential for diabetes management. However, current methods require people with diabetes to have blood test with 5-8 times per day. Compared to other methods, optical and magnetic techniques have a potential in developing minimally invasive or non-invasive, and continuous glucose monitoring nanostructured biosensors. Consequently, this thesis presented nanostructured optical and magnetic glucose biosensors by incorporating novel nanomaterials and fabricating nanostructures for the next generation of glucose biosensor in the tears. The glucose biorecognition biomolecule used in the biosensors was Concanavalin A (Con A). Con A is a lectin protein that has strong affinity to glucose. Fluorescence resonance energy transfer (FRET) technique was applied to develop optical glucose biosensors. FRET biosensor is a distance-dependent biosensor. The fluorescence emission of a donor molecule could be used to excite acceptor when the distance between donor and acceptor is close enough (\u3c 20 nm). Three different types of nanostructures were developed and used as the donors of the glucose FRET biosensors. The first type of sensor is a ZnO/quantum dots-based glucose biosensors. Hybrid ZnO nanorod array with decoration of CdSe/ZnS quantum dots were prepared and coated on silicone hydrogel which is a common materials of contact lens. The patterned nanostructured FRET sensor could quickly measure rats’ tear glucose in an extremely small amount (2 µL) of diluted tear sample. The second type of biosensor is based on upconversion nanomaterials. Upconversion NaGdF4: Yb, Er nanoparticles with diameter of about 40±5 nm have been prepared by polyol process and coated on silicone hydrogel to directly sense the tear glucose level on the rats’ eye surface. The results show that the upconversion nanomaterials based lens sensor is able to quickly measure glucose in rats’ blood samples. The third type of sensor utilizes the unique optical properties of carbon nanomaterial, fluorescent carbon dots and graphene oxide nanosheets. The carbon dots with tunable fluorescence were developed by a microwave-assisted process. The carbon dots are used as a fluorescence donor in the biosensor, the chitosan coated graphene oxide acts as the fluorescence acceptor to quench the emission of carbon quantum dots. In the presence of glucose, the emission of carbon quantum dots could be restored as a function of the concentration of glucose. Two linear relationships of the restored emission of the sensor and the concentration of glucose were observed, in the range of 0.2 mM to 1 mM, and 1 mM to 10 mM, respectively. On the other hand, a magnetoresistive (MR) nanostructured glucose biosensor has been developed by exploiting hybrid graphene nanosheets decorated with FeCo magnetic nanopartciles. The Fe3O4/silica core/shell nanoparticles are used as the magnetic label of glucose, which could bind onto the surface of FeCo/graphene nanocomposited sensor. The binding of magnetic label onto the hybrid graphene nanosheets can result in the change of the magnetoresistance. The MR signal as a function of the glucose level of diluted rat blood samples is measured in a range of 2 mM to 10 mM. In summary, novel nanomaterials and nanostructures with special fluorescent and magnetoresistive properties are fabricated for developing nanostructured glucose biosensors, which could bring alternative approaches for convenient management diabetes