PubMed İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://gcris.khas.edu.tr/handle/20.500.12469/4466

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Citation Count: 0
Paper integrated microfluidic contact lens for colorimetric glucose detection
(Royal Soc Chemistry, 2024) Istıf, Emın; Abbasiasl, Taher; Das, Ritu; Istif, Emin; Yener, Umut Can; Beker, Levent
Contact lenses offer a simple, cost-effective, and non-invasive method for in situ real-time analysis of various biomarkers. Electro-chemical sensors are integrated into contact lenses for analysis of various biomarkers. However, they suffer from rigid electronic components and connections, leading to eye irritation and biomarker concentration deviation. Here, a flexible and microfluidic integrated paper-based contact lens for colorimetric analysis of glucose was implemented. Facilitating a three-dimensional (3D) printer for lens fabrication eliminates cumbersome cleanroom processes and provides a simple, batch compatible process. Due to the capillary force of the filter paper, the sample was routed to detection chambers inside microchannels, and it allowed further colorimetric detection. The paper-embedded microfluidic contact lens successfully detects glucose down to 2 mM within similar to 10 s. The small dimension of the microfluidic system enables detection of glucose levels as low as 5 mu l. The results show the potential of the presented approach to analyze glucose concentration in a rapid manner. It is demonstrated that the fabricated contact lens can successfully detect glucose levels of diabetic patients. Contact lenses offer a simple, cost-effective, and non-invasive method for in situ real-time analysis of various biomarkers.
Citation Count: 19
Photolithography-Based Microfabrication of Biodegradable Flexible and Stretchable Sensors
(Wiley-V C H Verlag Gmbh, 2023) Istıf, Emın; Singh, Rahul; Mirzajani, Hadi; Istif, Emin; Akhtar, Muhammad Junaid; Abbasiasl, Taher; Beker, Levent
Biodegradable sensors based on integrating conductive layers with polymeric materials in flexible and stretchable forms have been established. However, the lack of a generalized microfabrication method results in large-sized, low spatial density, and low device yield compared to the silicon-based devices manufactured via batch-compatible microfabrication processes. Here, a batch fabrication-compatible photolithography-based microfabrication approach for biodegradable and highly miniaturized essential sensor components is presented on flexible and stretchable substrates. Up to 1600 devices are fabricated within a 1 cm(2) footprint and then the functionality of various biodegradable passive electrical components, mechanical sensors, and chemical sensors is demonstrated on flexible and stretchable substrates. The results are highly repeatable and consistent, proving the proposed method's high device yield and high-density potential. This simple, innovative, and robust fabrication recipe allows complete freedom over the applicability of various biodegradable materials with different properties toward the unique application of interests. The process offers a route to utilize standard micro-fabrication procedures toward scalable fabrication of highly miniaturized flexible and stretchable transient sensors and electronics.
Citation Count: 2
A Wearable Touch-Activated Device Integrated with Hollow Microneedles for Continuous Sampling and Sensing of Dermal Interstitial Fluid
(Wiley-v C H verlag Gmbh, 2023) Istıf, Emın; Mirlou, Fariborz; Mirzajani, Hadi; Bathaei, Mohammad Javad; Istif, Emin; Shomalizadeh, Narges; Beker, Levent
Dermal interstitial fluid (ISF) is emerging as a rich source of biomarkers that complements conventional biofluids such as blood and urine. However, the impact of ISF sampling in clinical applications has been limited owing to the challenges associated with extraction. The implementation of microneedle-based wearable devices that can extract dermal ISF in a pain-free and easy-to-use manner has attracted growing attention in recent years. Here, a fully integrated touch-activated wearable device based on a laser-drilled hollow microneedle (HMN) patch for continuous sampling and sensing of dermal ISF is introduced. The developed platform can produce and maintain the required vacuum pressure (as low as approximate to -53 kPa) to collect adequate volumes of ISF (approximate to 2 mu L needle-1 h-1) for medical applications. The vacuum system can be activated through a one-touch finger operation. A parametric study is performed to investigate the effect of microneedle array size, vacuum pressure, and extraction duration on collected ISF. The capability of the proposed platform for continuous health monitoring is further demonstrated by the electrochemical detection of glucose and pH levels of ISF in animal models. This HMN-based system provides an alternative tool to the existing invasive techniques for ISF collection and sensing for medical diagnosis and treatment. A fully-integrated touch-activated wearable device is developed for continuous sampling and electrochemical analysis of interstitial fluid. The elastic self-recovery of the vacuum generation system enables a wide range of negative pressures and extraction rates. The developed device can successfully detect glucose and pH levels and holds the potential for continuous sensing of multiple biomarkers in extracted interstitial fluid.image

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