Quantitative, Temperature-Calibrated and Real-Time Glucose Biosensor Based on Symmetrical-Meandering-Type Resistor and Intertwined Capacitor Structure

• Published in: Biosensors (Basel) 2021-11, Vol.11 (12), p.484
• Main Authors: Ma, Yangchuan, Qiang, Tian, Gao, Minjia, Liang, Junge, Jiang, Yanfeng
• Format: Article
• Language: English
• Subjects: Biomarkers; Biosensing Techniques; biosensor; Biosensors; Calibration; Capacitance; Capacitors; Diabetes; Dielectric properties; Electric Capacitance; Enzymes; Etching; Fluidity; Glass substrates; Glucose; Humidity; intertwined capacitor; Linearity; Medical research; microfluidic channel; Microfluidics; Monitoring; Physiology; Plating; Polydimethylsiloxane; Real time; Sensitivity; Sensors; symmetrical meandering type resistor; Temperature; temperature calibration; Temperature sensors
• ISSN: 2079-6374; 2079-6374
• DOI: 10.3390/bios11120484

Here, we propose a glucose biosensor with the advantages of quantification, excellent linearity, temperature-calibration function, and real-time detection based on a resistor and capacitor, in which the resistor works as a temperature sensor and the capacitor works as a biosensor. The resistor has a symmetrical meandering type structure that increases the contact area, leading to variations in resistance and effective temperature monitoring of a glucose solution. The capacitor is designed with an intertwined structure that fully contacts the glucose solution, so that capacitance is sensitively varied, and high sensitivity monitoring can be realized. Moreover, a polydimethylsiloxane microfluidic channel is applied to achieve a fixed shape, a fixed point, and quantitative measurements, which can eliminate influences caused by fluidity, shape, and thickness of the glucose sample. The glucose solution in a temperature range of 25-100 °C is measured with variations of 0.2716 Ω/°C and a linearity response of 0.9993, ensuring that the capacitor sensor can have reference temperature information before detecting the glucose concentration, achieving the purpose of temperature calibration. The proposed capacitor-based biosensor demonstrates sensitivities of 0.413 nF/mg·dL , 0.048 nF/mg·dL , and 0.011 pF/mg·dL ; linearity responses of 0.96039, 0.91547, and 0.97835; and response times less than 1 second, respectively, at DC, 1 kHz, and 1 MHz for a glucose solution with a concentration range of 25-1000 mg/dL.