Departament de Electricidad y Electrónica, Universidad del País Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), Barrio Sarriena s/n, 48940 Leioa, Spain.
BC Materials, Basque Center for Materials, Applications and Nanostructures, UPV/EHU Science Park, 48940 Leioa, Spain.
Sensors (Basel). 2020 May 14;20(10):2802. doi: 10.3390/s20102802.
The magnetoelastic resonance is used to monitor the precipitation reaction of calcium oxalate () crystals in real-time, by measuring the shift of the resonance frequency caused by the mass increase on the resonator. With respect to previous work on the same matter, the novelty lies in the adoption of an amorphous ferromagnetic alloy, of composition , as resonator, that replaces the commercial Metglas 2826 alloy (composition ). The enhanced corrosion resistance of this material allows it to be used in biological environments without any pre-treatment of its surface. Additionally, the measurement method, which has been specifically adapted to this application, allows quick registration of the whole resonance curve as a function of the excitation frequency, and thus enhances the resolution and decreases the detection noise. The frequency shift is calibrated by the static deposition of well-known masses of . The resonator dimensions have been selected to improve sensitivity. A 20 mm long, 2 mm wide and 25 m thick magnetoelastic resonator has been used to monitor the precipitation reaction of calcium oxalate in a 500 s time interval. The results of the detected precipitated mass when oxalic acid and calcium chloride are mixed in different concentrations (30 mM, 50 mM and 100 mM) are presented as a function of time. The results show that the sensor is capable of monitoring the precipitation reaction. The mass sensitivity obtained, and the corrosion resistance of the material, suggest that this material can perform excellently in monitoring this type of reaction.
磁弹共振用于实时监测草酸钙（）晶体的沉淀反应，通过测量由于谐振器上质量增加而引起的共振频率的位移来实现。与之前在同一主题上的工作相比，新颖之处在于采用了非晶态铁磁合金，其组成为，作为谐振器，取代了商用 Metglas 2826 合金（组成）。这种材料的增强耐腐蚀性使其可以在无需对其表面进行任何预处理的情况下用于生物环境中。此外，专门针对此应用而采用的测量方法允许快速注册整个共振曲线作为激励频率的函数，从而提高了分辨率并降低了检测噪声。通过静态沉积已知质量的来校准频率位移。选择谐振器尺寸以提高灵敏度。使用 20 毫米长、2 毫米宽和 25 微米厚的磁弹谐振器来监测在 500 秒时间间隔内草酸钙的沉淀反应。当草酸和氯化钙以不同浓度（30mM、50mM 和 100mM）混合时，检测到的沉淀质量的结果作为时间的函数呈现。结果表明，传感器能够监测沉淀反应。获得的质量灵敏度以及材料的耐腐蚀性表明，这种材料在监测此类反应方面表现出色。
