Browsing by Author "Unal, Mehmet Altay"

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Calibration of Quartz Tuning Fork transducer by coulometry for mass sensitive sensor studies
(2019) Dedeoglu, Aylin; Karadas, Nurgul; Unal, Mehmet Altay; Kocum, Ismail Cengiz; Serdaroglu, Dilek Cokeliler; Ozkan, Sibel Aysil
Mass-sensitive sensing has one main advantage: mass is one of the most fundamental properties of any analyte. They also require suitable recognition materials to ensure selectivity. Quartz Tuning Forks (QTFs) have been known as common oscillator components due to their stable resonant frequencies. In recent years, QTFs have started to be implemented as transducers into sensor systems which has the potential on resulting mass-sensitive sensors with high reliability. In this study, a developed QTF mass-sensitive sensor system has been utilized for applying calculations and finally formulizing the frequency to mass-load relationship for the standard 32,768 Hz QTF. Coulometric copper deposition method was used for a reliable mass-load that could be calculated consequently from the charge reduction measured through the potentiostat. Frequency changes were calculated through the measurements read on the QTF sensor system described. SEM imaging and SEM-EDX element analysis methods were used to assay and confirm the modification performed on the surface.
Design of a portable and low-cost mass-sensitive sensor with the capability of measurements on various frequency quartz tuning forks
(2019) Unal, Mehmet Altay; Kocum, Ismail Cengiz; Cokeliler Serdaroglu, Dilek; 0000-0001-8645-9047
Recently, sensor and biosensor applications have become widespread and are now significant tools in the biomedical field and other areas. Since quartz tuning fork (QTF) resonance frequency depends on the mass adsorbed to its prongs, it is generally used to measure minor mass change and detect target analyte in picogram levels. This study is undertaken to design and fabricate a sensor device for the measurement of QTF transducers. When QTF sensor studies were investigated, it was found that explanations on the details of instrumentation part were limited, and in addition, there was no compact commercial products. In this study, a novel, low-cost, portable quartz tuning fork sensor device with ability to work with any kind of display is presented in detail. Moreover, the effect of the ambient temperature during the measurements was checked. Six other QTF transducer types, 32, 32.768, 40, 65.536, 75, and 100 kHz, have been studied as the other novel part of the research. As a result, a QTF sensor device was fabricated that has further advanced features when compared with its alternatives and works with a more accurate measurement method. Owing to this advancement, using biosensor/chemical sensor which consists of QTF transducers with features that can take sensitive analyte measurement in picogram level will be able to spread.