WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/394
Browse
8 results
Search Results
Article Citation - WoS: 9Citation - Scopus: 11Size, Material Type, and Concentration Estimation for Micro-Particles in Liquid Samples(Elsevier Science SA, 2024-05) Genc, Sinan; Erdem, Talha; Icoz, KutayThe on -site examination and characterization of microparticles are becoming crucial due to the significant rise in plastic pollution in natural resources. Hence, identifying the specific microplastic composition and quantity would enable the implementation of preventive measures. This paper presents a cost-effective setup that utilizes the Random Forest algorithm to detect the size and refractive index of micro particles, hence facilitating the identification of the material type. The system utilizes the scattering patterns of laser light from the dispersion of microparticles, namely within the concentration range of 0.05 fM to 3.00 fM. The refractive indices and particle sizes of melamine (Me8) spheres with a size of 8 mu m, as well as polystyrene (PS8) spheres with a size of 8 mu m and (PS10) 10 mu m, were estimated using the Random Forest algorithm and recorded scattering patterns. The proposed method may deliver findings with an average deviation of 0.23 mu m for particle size and 0.015 for particle refractive index. The statistical analysis indicated that there was no notable disparity between the experimental findings and the predictions derived from the machine learning system. The existing configuration can be readily converted into a point -of -use system that can be employed on -site for the purpose of monitoring and identifying microplastic contamination.Article Citation - WoS: 3Citation - Scopus: 6Simple Staining of Cells on a Chip(MDPI, 2022-11-13) Kosker, Fatma Betul; Aydin, Omer; Icoz, KutaySimple staining of cells is a widely used method in basic medical diagnostics, education, and research laboratories. The stains are low-cost, but the extensive consumption results in excessive toxic waste generation. Thus, to decrease the amount of toxic waste resulting from the cell staining procedure is a need. In this study, we developed a magnetically driven and compartmentalized passive microfluidic chip to perform simple staining of human eukaryotic cells, K562 cells, and lymphocyte cells derived from patients. We demonstrated simple staining on cells with trypan blue, methylene blue, crystal violet, and safranin for high, medium, and low cell densities. The stained cells were imaged using a bright field optical microscope and a cell phone to count cells on the focal plane. The staining improved the color signal of the cell by 25-135-pixel intensity changes for the microscopic images. The validity of the protocol was determined using Jurkat and MDA-MB-231 cell lines as negative controls. In order to demonstrate the practicality of the system, lymphocyte cells derived from human blood samples were stained with trypan blue. The color intensity changes in the first and last compartments were analyzed to evaluate the performance of the chip. The developed method is ultra-low cost, significantly reduces the waste generated, and can be integrated with mobile imaging devices in terms of portability. By combining microfabrication technology with cell staining, this study reported a novel contribution to the field of microfluidic biosensors. In the future, we expect to demonstrate the detection of pathogens using this method.Article Citation - WoS: 18Citation - Scopus: 20Respiration Monitoring Using a Paper-Based Wearable Humidity Sensor, a Step Forward to Clinical Tests(Elsevier Science SA, 2023-06) Solak, Irfan; Gencer, Serife; Yildirim, Beyza; Oznur, Emine; Hah, Dooyoung; Icoz, KutayMonitoring respiratory variables can provide valuable information for clinical applications and sport activities. Paper-based wearable respiration monitoring systems have great advantages and potential, they are low-cost, easily disposable, non-invasive and can provide real-time, reliable data. Despite some examples presented for exhaled breath analysis using paper-based sensors exist, none of them have been validated yet in a study involving many patients. In this work, we present a novel paper-based platform for exhaled breath sensors and validate it on 101 subjects including 41 patients to demonstrate its clinical applicability. By using the paperbased wearable capacitive sensors, we collected respiration data from different groups of people, namely, smokers, non-smokers and patients diagnosed with pneumonia, or chronic obstructive pulmonary disease (COPD). The change in humidity during inhale and exhale was converted to capacitance change and thus an electrical signal was obtained. The electrical signal was transmitted to a nearby computer and capacitance versus time data was post-processed. Four ratio parameters were defined on the recorded data; area, rate, maximum amplitude, and average maximum-minimum difference, all of which were compared between deep breathing and normal breathing. The collected data was statistically analyzed, and the humidity changes were compared among different groups. The results show that the developed sensor and the proposed analysis method can be used to detect the humidity changes in breathing, and to differentiate between smokers and non-smokers, and between non-smokers and patients with pulmonary disease.Article Citation - WoS: 16Citation - Scopus: 19On-Demand Weighing of Single Dry Biological Particles Over a 5-Order Dynamic Range(Royal Soc Chemistry, 2014) Chan, Bin-Da; Icoz, Kutay; Huang, Wanfeng; Chang, Chun-Li; Savran, Cagri A.We report a simple and highly versatile system to select and weigh individual dry biological particles. The system is composed of a microtweezer to pick and place individual particles and a cantilever-based resonator to weigh them. The system can weigh entities that vary from a red blood cell (similar to 10(-11) g) to the eye-brain complex of an insect (similar to 10(-6) g), covering a 5-order-of-magnitude mass range. Due to its versatility and ease of use, this weighing method is highly compatible with established laboratory practices. The system can provide complementary mass information for a wide variety of individual particles imaged using scanning electron microscopy and determine comparative weights of individual biological entities that are attached to microparticles as well as weigh fractions of individual biological entities that have been subjected to focused ion beam milling.Article Citation - WoS: 28Citation - Scopus: 34Micro- and Nanodevices Integrated With Biomolecular Probes(Pergamon-Elsevier Science Ltd, 2015-12) Alapan, Yunus; Icoz, Kutay; Gurkan, Umut A.Understanding how biomolecules, proteins and cells interact with their surroundings and other biological entities has become the fundamental design criterion for most biomedical micro- and nanodevices. Advances in biology, medicine, and nanofabrication technologies complement each other and allow us to engineer new tools based on biomolecules utilized as probes. Engineered micro/nanosystems and biomolecules in nature have remarkably robust compatibility in terms of function, size, and physical properties. This article presents the state of the art in micro- and nanoscale devices designed and fabricated with biomolecular probes as their vital constituents. General design and fabrication concepts are presented and three major platform technologies are highlighted: microcantilevers, micro/nanopillars, and microfluidics. Overview of each technology, typical fabrication details, and application areas are presented by emphasizing significant achievements, current challenges, and future opportunities. (C) 2015 Elsevier Inc. All rights reserved.Article Citation - WoS: 15Citation - Scopus: 16Magnetic Micro/Nanoparticle Flocculation-Based Signal Amplification for Biosensing(Dove Medical Press Ltd, 2016-06) Mzava, Omary; Tas, Zehra; Icoz, KutayWe report a time and cost efficient signal amplification method for biosensors employing magnetic particles. In this method, magnetic particles in an applied external magnetic field form magnetic dipoles, interact with each other, and accumulate along the magnetic field lines. This magnetic interaction does not need any biomolecular coating for binding and can be controlled with the strength of the applied magnetic field. The accumulation can be used to amplify the corresponding pixel area that is obtained from an image of a single magnetic particle. An application of the method to the Escherichia coli 0157: H7 bacteria samples is demonstrated in order to show the potential of the approach. A minimum of threefold to a maximum of 60-fold amplification is reached from a single bacteria cell under a magnetic field of 20 mT.Article Citation - WoS: 14Citation - Scopus: 15Image-Analysis Based Readout Method for Biochip: Automated Quantification of Immunomagnetic Beads, Micropads and Patient Leukemia Cell(Pergamon-Elsevier Science Ltd, 2020-06) Uslu, Fatma; Icoz, Kutay; Tasdemir, Kasim; Dogan, Refika S.; Yilmaz, BulentFor diagnosing and monitoring the progress of cancer, detection and quantification of tumor cells is utmost important. Beside standard bench top instruments, several biochip-based methods have been developed for this purpose. Our biochip design incorporates micron size immunomagnetic beads together with micropad arrays, thus requires automated detection and quantification of not only cells but also the micropads and the immunomagnetic beads. The main purpose of the biochip is to capture target cells having different antigens simultaneously. In this proposed study, a digital image processing-based method to quantify the leukemia cells, immunomagnetic beads and micropads was developed as a readout method for the biochip. Color, size-based object detection and object segmentation methods were implemented to detect structures in the images acquired from the biochip by a bright field optical microscope. It has been shown that manual counting and flow cytometry results are in good agreement with the developed automated counting. Average precision is 85 % and average error rate is 13 % for all images of patient samples, average precision is 99 % and average error rate is 1% for cell culture images. With the optimized micropad size, proposed method can reach up to 95 % precision rate for patient samples with an execution time of 90 s per image.Article Citation - WoS: 3Citation - Scopus: 6High Spatial Resolution IoT Based Air PM Measurement System(Springer, 2021-04-12) Icoz, Ebru; Malik, Fasih M.; Icoz, KutayAir pollution is one of the global problems of the current era. According to World Health Organization more than 80% of the people living in metropolitan areas breathe air which exceeds the guideline limits. Particulate matter, the mixture of liquid and solid particles having diameters less than 10 mu m, is one of the important pollutants in the air. The main source of the Particulate matter is mostly burning reactions associated with industry, vehicles and homes. Several studies have shown the lethal impact of particulate matter to public health and environment. The rise of particulate matter amount in air has been linked to several health problems such as not only respiratory diseases but also mortality in infants and heart attacks. Currently, bulky stations which are high-cost and have limited spatial resolution are used to monitor the air quality. In this study we developed an alternative particulate matter measurement system which is portable and low-cost (less than 200 USD) and also integrated with cloud computing. The system allows real time distant monitoring of PM particles with high spatial resolution (meter range). The developed sensor system is able to provide air quality data in correlation with the existing stations (R-2 = 0.87). The statistical comparison between the developed system and the reference methods revealed that two systems produced statistically equal results in detecting the variations of the particulate matter.