Browsing by Subject "Biosensors"

Now showing 1 - 20 of 23

Open Access
Advances in biosensor technologies for acute kidney injury
(American Chemical Society, 2021-12-20) Derin, Esma; İnci, Fatih
Acute kidney injury (AKI) is one of the most prevalent and complex clinical syndromes with high morbidity and mortality. The traditional diagnosis parameters are insufficient regarding specificity and sensitivity, and therefore, novel biomarkers and their facile and rapid applications are being sought to improve the diagnostic procedures. The biosensors, which are employed on the basis of electrochemistry, plasmonics, molecular probes, and nanoparticles, are the prominent ways of developing point-of-care devices, along with the mutual integration of efficient surface chemistry strategies. In this manner, biosensing platforms hold pivotal significance in detecting and quantifying novel AKI biomarkers to improve diagnostic interventions, potentially accelerating clinical management to control the injury in a timely manner. In this review, novel diagnostic platforms and their manufacturing processes are presented comprehensively. Furthermore, strategies to boost their effectiveness are also indicated with several applications. To maximize these efforts, we also review various biosensing approaches with a number of biorecognition elements (e.g., antibodies, aptamers, and molecular imprinting molecules), as well as benchmark their features such as robustness, stability, and specificity of these platforms.
Open Access
Assembly kinetics of nanocrystals via peptide hybridization
(American Chemical Society, 2011-03-16) Seker U.O.S.; Zengin, G.; Tamerler, C.; Sarikaya, M.; Demir, Hilmi Volkan
The assembly kinetics of colloidal semiconductor quantum dots (QDs) on solid inorganic surfaces is of fundamental importance for implementation of their solid-state devices. Herein an inorganic binding peptide, silica binding QBP1, was utilized for the self-assembly of nanocrystal quantum dots on silica surface as a smart molecular linker. The QD binding kinetics was studied comparatively in three different cases: first, QD adsorption with no functionalization of substrate or QD surface; second, QD adsorption on QBP1-modified surface; and, finally, adsorption of QBP1-functionalized QD on silica surface. The surface modification of QDs with QBP1 enabled 79.3-fold enhancement in QD binding affinity, while modification of a silica surface with QBP1 led to only 3.3-fold enhancement. The fluorescence microscopy images also supported a coherent assembly with correspondingly increased binding affinity. Decoration of QDs with inorganic peptides was shown to increase the amount of surface bound QDs dramatically compared to the conventional methods. These results offer new opportunities for the assembly of QDs on solid surfaces for future device applications.
Open Access
Carbon-based nanomaterials and sensing tools for wearable health monitoring devices
(Wiley-VCH Verlag GmbH & Co. KGaA, 2021-10-05) Erdem, Özgecan; Derin, Esma; Shirejini, Saeedreza Zeibi; Sağdıç, Kutay; Yılmaz, Eylül Gülşen; Yıldız, Selvin; Akçeoğlu, Garbis Atam; İnci, Fatih
The healthcare system has a drastic paradigm shift from centralized care to home-based and self-monitoring strategies; aiming to reach more individuals, minimize workload in hospitals, and reduce healthcare-associated expenses. Particularly, wearable technologies are garnering considerable interest by tracking physiological parameters through motion and activities, and monitoring biochemical markers from sweat, saliva, and tears. Through their integrations with sensors, microfluidics, and wireless communication systems, they allow physicians, family members, or individuals to monitor multiple parameters without any significant disruptions to daily routine. Integrating flexible and smart materials with wearable platforms have already enabled facile operations. Especially, carbon nanomaterials hold unique features, including low density, high strength, good conductivity, outstanding flexibility, versatile integration with materials and sensors. In this manuscript, carbon nanomaterials are comprehensively reviewed with their tremendous assets utilized in wearable technologies. Further, their integration with ultrasonic, acoustic and energy harvesting devices, optical and electrochemical platforms, microfluidics, and wireless communication technologies are presented.
Open Access
Continuous triboelectric power harvesting and biochemical sensing inside poly(vinylidene fluoride) hollow fibers using microfluidic droplet generation
(Wiley-Blackwell, 2016-11) Kanik, M.; Marcali, M.; Yunusa, M.; Elbuken, C.; Bayındır, Mehmet
Triboelectric power harvesting and biochemical sensing inside poly(vinylidene fluoride) hollow fibers. Fiber‐based microfluidic energy harvesting system, which is also utilized as self‐powered chemical and biosensor. In vitro device concept demonstrating that triboelectric effect can be used for cell detection.
Open Access
Design of synthetic biological devices for detection and targeting human diseases
(Elsevier, 2022-01-01) Hacıosmanoğlu, Nedim; Köse, Sıla; Ostaku, Julian; Köksaldi, İlkay Çisil; Saltepe, Behide; Şeker, Urartu Özgür Şafak; Singh, V.
Interpreting signals coming from the surrounding environment and responding to these stimuli by adjusting physical or metabolic state is the most fundamental ability of living organisms. Repurposing these natural abilities for the detection and responding to different molecules is one of the key focuses of synthetic biology because the overall strategy could provide advanced solutions for different diseases. Also by being naturally suitable to the design-build-test-learn manner of synthetic biology, biosensors are great examples of what engineering and biology could achieve when they come together. Literature has many examples of intellectually designed biosensor systems, which may overachieve and outperform existing technologies with a completely biocompatible structure. In this chapter, design and application of these biosensor systems will be investigated.
Open Access
Developing a transducer based on localized surface plasmon resonance (LSPR) of gold nanostructures for nanobiosensor applications
(Trans Tech Publications, 2013) Turhan, Adil Burak; Ataman, D.; Çakmakyapan, S.; Mutlu, M.; Özbay, Ekmel; Vlachos, D. S.; Hristoforou, E.
In this work, we report the nanofabrication, optical characterization, and electromagnetic modeling of various nanostructure arrays for localized surface plasmon resonance (LSPR) based biosensing studies. Comparison of the experimental results and simulation outputs of various nanostructure arrays was made and a good correspondence was achieved.
Open Access
Electron beam lithography designed silver nano-disks used as label free nano-biosensors based on localized surface plasmon resonance
(Optical Society of America, 2012-01-20) Cinel, N. A.; Butun, S.; Özbay, Ekmel
We present a label-free, optical nano-biosensor based on the Localized Surface Plasmon Resonance (LSPR) that is observed at the metaldielectric interface of silver nano-disk arrays located periodically on a sapphire substrate by Electron-Beam Lithography (EBL). The nano-disk array was designed by finite-difference and time-domain (FDTD) algorithm-based simulations. Refractive index sensitivity was calculated experimentally as 221-354 nm/RIU for different sized arrays. The sensing mechanism was first tested with a biotin-avidin pair, and then a preliminary trial for sensing heat-killed Escherichia coli (E. coli) O157:H7 bacteria was done. Although the study is at an early stage, the results indicate that such a plasmonic structure can be applied to bio-sensing applications and then extended to the detection of specific bacteria species as a fast and low cost alternative. © 2012 Optical Society of America.
Open Access
Glucose sensors based on electrospun nanofibers: a review
(Springer Verlag, 2016) Senthamizhan, A.; Balusamy, B.; Uyar, Tamer
The worldwide increase in the number of people suffering from diabetes has been the driving force for the development of glucose sensors. The recent past has devised various approaches to formulate glucose sensors using various nanostructure materials. This review presents a combined survey of these various approaches, with emphasis on the current progress in the use of electrospun nanofibers and their composites. Outstanding characteristics of electrospun nanofibers, including high surface area, porosity, flexibility, cost effectiveness, and portable nature, make them a good choice for sensor applications. Particularly, their nature of possessing a high surface area makes them the right fit for large immobilization sites, resulting in increased interaction with analytes. Thus, these electrospun nanofiber-based glucose sensors present a number of advantages, including increased life time, which is greatly needed for practical applications. Taking all these facts into consideration, we have highlighted the latest significant developments in the field of glucose sensors across diverse approaches.
Open Access
Hybridization of fano and vibrational resonances in surface-enhanced infrared absorption spectroscopy of streptavidin monolayers on metamaterial substrates
(2014) Alici, K. B.
We present spectral hybridization of organic and inorganic resonant materials and related bio-sensing mechanism. We utilized a bound protein (streptavidin) and a Fano-resonant metasurface to illustrate the concept. The technique allows us to investigate the vibrational modes of the streptavidin and how they couple to the underlying metasurface. This optical, label-free, nonperturbative technique is supported by a coupled mode-theory analysis that provides information on the structure and orientation of bound proteins. We can also simultaneously monitor the binding of analytes to the surface through monitoring the shift of the metasurface resonance. All of this data opens up interesting opportunities for applications in biosensing, molecular electronics and proteomics. © 2014 IEEE.
Open Access
In situ synthesis of biomolecule encapsulated gold-cross-linked poly(ethylene glycol) nanocomposite as biosensing platform: A model study
(Elsevier BV, 2010) Odaci, D.; Kahveci, M.U.; Sahkulubey, E.L.; Ozdemir, C.; Uyar, Tamer; Timur, S.; Yagci Y.
In situ synthesis of poly(ethylene glycol) (PEG) hydrogels containing gold nanoparticles(AuNPs) and glucose oxidase (GOx) enzyme by photo-induced electron transfer process was reported here and applied in electrochemical glucose biosensing as the model system. Newly designed bionanocomposite matrix by simple one-step fabrication offered a good contact between the active site of the enzyme and AuNPs inside the network that caused the promotion in the electron transfer properties that was evidenced by cyclic voltammetryas well as higher amperometric biosensing responses in comparing with response signals obtained from the matrix without AuNPs. As well as some parameters important in the optimization studies such as optimum pH, enzyme loading and AuNP amount, the analytical characteristics of the biosensor (AuNP/GOx) were examined by the monitoring of chronoamperometric response due to the oxygen consumption through the enzymatic reaction at − 0.7 V under optimized conditions at sodium acetate buffer (50 mM, pH 4.0) and the linear graph was obtained in the range of 0.1–1.0 mM glucose. The detection limit (LOD) of the biosensor was calculated as 0.06 mM by using the signal to noise ratio of 3. Moreover, the presence of AuNPs was visualized by TEM. Finally, the biosensor was applied for glucose analysis for some beverages and obtained data were compared with HPLC as the reference method to test the possible matrix effect due to the nature of the samples.
Open Access
Multimode microwave sensors for microdroplet and single-cell detection
(2018-08) Aydoğmuş, Hande
A novel detection mechanism which can reveal both morphological and electrical properties of analytes are needed for Lab-on-a-Chip applications. Herein, a label-free, real-time and non-contact detection paradigm in microwave domain is constructed, by using rst and second electromagnetic modes of a microwave resonator. As the resonator, microstrip line is chosen since it o ers accessible boundary conditions. In order to deliver the analytes into the sensing region, micro uidic channels are fabricated. As a proof-of-concept, while the microstrip line resonator's rst and second modes are tracked simultaneously, analytes are delivered through the microchannel embedded underneath the signal layer. As the analytes, water microdroplets in oil, cervical (HeLa) and breast (MDA-MB-157) cancer cells in their appropriate medium are used and detected; their position and electrical volume informations are obtained and compared. Allan Deviation of the measurement is smaller than 2 10􀀀8 for both modes, and due to analyte properties in microwave domain, such as the great permittivity di erence between the biological analyte and medium, detection is possible. In order to test the accuracy of nding the position of the analyte, two di erent microchannel geometries are designed. The rst geometry is based on a zigzag channel, where microstrip line crosses the channel at 6 di erent locations. Secondly, a branched channel is designed, to send the microdroplets at four di erent locations. This delivery mechanism is mostly based on the hydraulic resistance: Each droplet chooses its path by the hydraulic resistance that is caused by the previous droplet. Hence, microdroplets are distributed to four channels. Due to the mode shape of the speci c mode, when analyte passing through these regions, it induces di erent frequency shifts. For these applications, micro uidic part is fabricated by conventional soft lithography methods, and the material for the microchannels is PDMS. Electrical volume of the droplets is also obtained. After the usage of prototypes for position and electrical volume calculations, second generation devices are fabricated. Compared to the PDMS-based devices, these devices o er rapid and low-cost prototyping. Additionally, Kapton is chosen for the dielectric material, and it has some material-wise bene ts, such as the tangent loss level. Analytes are delivered through the sensing region by capillary tubings, hence soft lithography steps can be eliminated. Due to the equipment limitations, only the rst mode is tracked with these novel devices, while another type of breast cancer cells (SK-BR-3) are delivered through the sensing region. Signal-to-noise ratio, when compared to the PDMS based devices, is improved. In this work, the rst two modes of microstrip line resonators are used. However, by using higher order modes, more properties about the particles as skewness, geometrical volume, orientation, and composition can be obtained. These informations can be used to construct a global image of the analyte; rather than a pixel by pixel image. Additionally, ow cytometry applications, detection of Circulating Tumour Cells and applications for long term cultivation on chip (also known as Organ-on-Chip platforms) can be achieved.
Open Access
Peptide-mediated constructs of quantum dot nanocomposites for enzymatic control of nonradiative energy transfer
(American Chemical Society, 2011) Seker U.O.S.; Ozel, T.; Demir, Hilmi Volkan
A bottom-up approach for constructing colloidal semiconductor quantum dot (QDot) nanocomposites that facilitate nonradiative Förster-type resonance energy transfer (FRET) using polyelectrolyte peptides was proposed and realized. The electrostatic interaction of these polypeptides with altering chain lengths was probed for thermodynamic, structural, and morphological aspects. The resulting nanocomposite film was successfully cut with the protease by digesting the biomimetic peptide layer upon which the QDot assembly was constructed. The ability to control photoluminescence decay lifetime was demonstrated by proteolytic enzyme activity, opening up new possibilities for biosensor applications.
Open Access
Plasmonic nanoparticle based nanobiosensors and nanophotodetectors
(SPIE, 2013) Cinel, N.A.; Bütün, S.; Özbay, Ekmel
Plasmonics mainly deals with light-matter interactions in metallic nanostructures. It has gathered interest since its discovery due to the benefits it provides when compared with photonics and electronics. It owes its popularity to the tremendous number of applications it serves for. In this paper, we review how plasmonic nanoparticles can be utilized in applications such as localized surface plasmon resonance based biosensing and enhancing performance of photodetectors. © 2013 SPIE.
Open Access
Plasmonic nanoparticle based nanobiosensors and nanophotodetectors
(SPIE, 2013) Cinel, Neval A.; Bütün, S.; Özbay, Ekmel
Plasmonics mainly deals with light-matter interactions in metallic nanostructures. It has gathered interest since its discovery due to the benefits it provides when compared with photonics and electronics. It owes its popularity to the tremendous number of applications it serves for. In this paper, we review how plasmonic nanoparticles can be utilized in applications such as localized surface plasmon resonance based biosensing and enhancing performance of photodetectors. © 2013 SPIE.
Open Access
Real-time and selective detection of single nucleotide DNA mutations using surface engineered microtoroids
(American Chemical Society, 2015) Toren, P.; Ozgur E.; Bayındır, Mehmet
Mictoroids, as optical biosensors, can provide beneficial biosensing platforms to understand DNA alterations. These alterations could have significant clinical importance, such as the case of Pseudomonas aeruginosa, which is a commonly found pathogen in Cystic Fibrosis (CF) patients-causing poor prognosis by undergoing mutations during disease steps, gaining virulence and drug resistance. To provide a preliminary diagnosis platform for early-stage bacterial mutations, biosensing with a selective microtoroid surface was suggested. For this purpose, microtoroids with high quality factors were fabricated. The microtoroid surfaces were coated with (3-aminopropyl) triethoxysilane (APTES)/trimethylmethoxysilane (TMMS) mixed silane solution followed by EDC/NHS chemistry for covalent conjugation of DNA probes. Ethanolamine capping was applied to avoid unspecific interactions. The confocal studies confirmed homogeneous functionalization of the microtoroid surface. The DNA hybridization was demonstrated to be affected from the probe length. The optical biosensors showed a significant response (∼22 pm) to the complementary strand of the mutated type P. aeruginosa DNA, while showing substantially low and late response (∼5 pm) to the point mismatch strand. The limit of detection (LOD) for the complementary strand was calculated as 2.32 nM. No significant response was obtained for the noncomplementary strand. The results showed the microtoroids possessed selective surfaces in terms of distinguishing DNA alterations.
Open Access
Real-time biosensing bacteria and virus with quartz crystal microbalance: recent advances, opportunities, and challenges
(Taylor & Francis, 2023-05-16) Bonyadi, Farzaneh; Kavruk, Murat; Uçak, Samet; Çetin, Barbaros; Bayramoğlu, Gülay; Dursun, Ali D.; Arıca, Yakup; Özalp, Veli C.
Continuous monitoring of pathogens finds applications in environmental, medical, and food industry settings. Quartz crystal microbalance (QCM) is one of the promising methods for real-time detection of bacteria and viruses. QCM is a technology that utilizes piezoelectric principles to measure mass and is commonly used in detecting the mass of chemicals adhering to a surface. Due to its high sensitivity and rapid detection times, QCM biosensors have attracted considerable attention as a potential method for detecting infections early and tracking the course of diseases, making it a promising tool for global public health professionals in the fight against infectious diseases. This review first provides an overview of the QCM biosensing method, including its principle of operation, various recognition elements used in biosensor creation, and its limitations and then summarizes notable examples of QCM biosensors for pathogens, focusing on microfluidic magnetic separation techniques as a promising tool in the pretreatment of samples. The review explores the use of QCM sensors in detecting pathogens in various samples, such as food, wastewater, and biological samples. The review also discusses the use of magnetic nanoparticles for sample preparation in QCM biosensors and their integration into microfluidic devices for automated detection of pathogens and highlights the importance of accurate and sensitive detection methods for early diagnosis of infections and the need for point-of-care approaches to simplify and reduce the cost of operation.
Open Access
SILVER nano-cylinders designed by EBL used as label free LSPR nano-biosensors
(SPIE, 2011) Cinel, Neval A.; Bütün, Serkan; Özbay, Ekmel
Localized Surface Plasmon Resonance (LSPR) is based on the electromagnetic-field enhancement of metallic nano-particles. It is observed at the metal-dielectric interface and the resonance wavelength can be tuned by the size, shape, and periodicity of the metallic nanoparticles and the surrounding dielectric environment. This makes LSPR a powerful candidate in bio-sensing. In the present work, the size and period dependency of the LSPR wavelength was studied through simulations and fabrications. The surface functionalization, that transforms the surface into a sensing platform was done and verified. Finally, the concentration dependency of the LSPR shifts was observed. All the measurements were done by a transmission set-up. The study is at an early stage, however results are promising. The detection of specific bacteria species can be made possible with such a detection method. © 2011 SPIE.
Open Access
Smart materials: Rational design in biosystems via artificial intelligence
(Cell Press, 2022-02-28) Sağdıç, Kutay; Eş, İ.; Sitti, M.; İnci, Fatih
Industry 4.0 encompasses a new industrial revolution in which advanced manufacturing systems are interconnected with information technologies. These sophisticated data-gathering technologies have led to a shift toward smarter manufacturing processes involving the use of smart materials (SMs). The properties of SMs make them highly attractive for numerous biomedical applications. The integration of artificial intelligence (AI) enables them to be effectively used in the design of novel biomedical platforms to overcome shortcomings in the current biotechnology industry. This review summarizes recent advances in AI-assisted SMs for different healthcare products. The current challenges and future perspectives of AI-supported smart biosystems are also discussed, particularly with the regard to their applications in drug design, biosensors, theranostics, and electronic skins.
Open Access
A smartphone based surface plasmon resonance imaging (SPRi) platform for on-site biodetection
(Elsevier, 2017) Guner, H.; Ozgur, E.; Kokturk, G.; Celik, M.; Esen, E.; Topal, A. E.; Ayas, S.; Uludag, Y.; Elbuken, C.; Dana, A.
We demonstrate a surface plasmon resonance imaging platform integrated with a smartphone to be used in the field with high-throughput biodetection. Inexpensive and disposable SPR substrates are produced by metal coating of commercial Blu-ray discs. A compact imaging apparatus is fabricated using a 3D printer which allows taking SPR measurements from more than 20.000 individual pixels. Real-time bulk refractive index change measurements yield noise equivalent refractive index changes as low as 4.12 × 10−5 RIU which is comparable with the detection performance of commercial instruments. As a demonstration of a biological assay, we have shown capture of mouse IgG antibodies by immobilized layer of rabbit anti-mouse (RAM) IgG antibody with nanomolar level limit of detection. Our approach in miniaturization of SPR biosensing in a cost-effective manner could enable realization of portable SPR measurement systems and kits for point-of-care applications.
Open Access
A snapshot of microfluidics in point-of-care diagnostics: multifaceted integrity with materials and sensors
(Wiley-VCH Verlag GmbH & Co. KGaA, 2021-05-09) Akçeoğlu, Garbis Atam; Saylan, Y.; İnci, Fatih
Over four decades, point-of-care (POC) technologies and their pivotal applications in the biomedical arena have increased irrepressibly and allowed to realize the potential of portable and accurate diagnostic strategies. Today, in the light of these advances, POC systems dominate the medical inventions and bring the diagnostics to the bedside settings, potentially minimizing the workload in the centralized laboratories, as well as remarkably reducing the associated-cost and time. In contrast to the conventional technologies, microfluidics paves the way to create more efficient and applicable POC diagnostic devices through their inherent fashions such as minute volume of samples, easy manipulations, shorter assay time, and low-cost production. In this review, the current status and advancements of microfluidic systems along with the current limitations in the aspect of POC diagnostic strategies are elaborated. Further, the integration of novel materials and innovative sensing platforms to the microfluidic systems are comprehensively evaluated to address the real-world challenges for diagnosing various maladies at the POC settings.