Min-Siang Huang

Dynamic and Wireless Sensing Measurements of Potentiometric Glucose Biosensor Based on Graphene and Magnetic Beads

In this paper, the arrayed flexible pH sensor and glucose biosensor modified by magnetic beads and graphene were proposed. The ruthenium dioxide (RuO2) sensing films were deposited by radio frequency sputtering system and the screen-printed technique was used to construct the silver conducting wires and insulation layer of the RuO2 electrodes. In order to enhance performance of the pH sensor and glucose biosensor, the microfluidic device had been utilized and developed. In the measurement processes, the different pH and glucose solutions were investigated in various flow rates. According to the experimental results, the average sensitivity of the pH sensor was enhanced from 52.280 to 57.981 mV/pH and the average sensitivity of the RuO2/graphene/magnetic bead-GOx-Nafion glucose biosensor was enhanced from 10.628 to 13.541 mV/mM. With regard to the wireless sensing measurements, the wireless sensing system which complied the ZigBee standard was employed to transmit the signals of the pH or glucose measurements in this investigation, and the system consisted of the Xbee device, Arduino Mega 2560, readout circuit, pH or glucose biosensor and computer. According to the experimental results, the average sensitivity and linearity of the pH sensor were 51.063 mV/pH and 0.988, respectively, and the average sensitivity and linearity of the RuO2/graphene/magnetic bead-GOx-Nafion glucose biosensor were 11.005 mV/mM and 0.995, respectively.

Research of Non-Ideal Effect and Dynamic Measurement of the Flexible-Arrayed Chlorine Ion Sensor

This paper investigated the sensing characteristics of a flexible-arrayed chlorine ion sensor, which was realized based on ruthenium oxide thin-film/polyethylene terephthalate substrate and fabricated by the screen-printed technology and the radio frequency sputtering technique. By the static measurement, the average sensitivity and the linearity of the chlorine ion sensor were 25.065 mV/pCl and 0.960 from 10-5 to 1 M sodium chloride (NaCl) solutions. This paper also investigated the non-ideal effect and dynamic microfluidic measurement for the flexible-arrayed chlorine ion sensor. The hysteresis potential of the flexible-arrayed chlorine ion sensor was 2.738 mV in the NaCl solutions with the cycle of 1 M → 10-3 M → 1 M → 10-1 M → 1 M. Besides, we measured the response potentials in different concentrations from 10-5 to 1 M NaCl solutions over 12 h, and the best drift rate of the chloride ion sensor was 0.454 mV/h in 10-2 M NaCl solution. By the dynamic measurement of the flexible-arrayed chlorine ion sensor, the average sensitivity and the linearity were 30.758 mV/pCl and 0.985 for the flow rate of 25 μL/min between 10-5 and 1 M NaCl solutions. Therefore, the average sensitivity and the linearity of the dynamic measurement were better than those of the static measurement for the flexible-arrayed chlorine ion sensor.

The Characteristic Analysis of IGZO/Al pH Sensor and Glucose Biosensor in Static and Dynamic Measurements

In this paper, the pH sensor and glucose biosensor were integrated with microfluidic framework, and the sensing characteristics under the dynamic conditions, i.e., solution under flowing condition, were investigated. The indium-gallium-zinc oxide (IGZO), as a sensing membrane, was deposited on aluminum electrodes/polyethylene terephthalate substrate. Then, the screen-printed technology was used to accomplish the encapsulation of sensor. The glucose biosensor based on enzyme needed an extra glucose sensing membrane, which was composed of glucose oxidase (GOx) and nafion. The glucose sensing membrane was dropped on the IGZO/Al sensing membrane. According to the experimental results, the optimal sensing characteristics of pH sensor and glucose biosensor under the dynamic conditions were better than those under the static condition (solution without flowing). The optimal average sensitivity and linearity were 56.857 mV/pH and 0.997 at 25 μL/min flow rate, respectively (in pH sensor), and 7.255 mV/mM and 0.994 at 20 μL/min flow rate, respectively (in glucose biosensor). Furthermore, the hysteresis effect and drift effect were researched for pH sensor, and the electrochemical impedance spectroscopy was used to demonstrate whether the IGZO/Al sensing membrane had been modified by GOx and nafion and it was found that the additions of GOx and nafion had increased the electron transfer resistance (Ret).

Wireless Sensing System for Flexible Arrayed Potentiometric Sensor Based on XBee Module

In this paper, the wireless sensor network (WSN) with the ZigBee standard is integrated with the flexible arrayed potentiometric sensor, such as flexible arrayed pH sensor and flexible arrayed glucose biosensor that achieve a wireless sensing system. The wireless sensing system is accomplished by the graphical language laboratory virtual instrumentation engineering workbench and the detection signals are displayed in real time in the computer. A potentiometric electrochemical method is used to measure the output signal of potential difference between the silver/silver chloride (Ag/AgCl) reference electrode and the flexible arrayed potentiometric sensor. We provide a wireless sensing system of XBee module, which has the advantages of low cost, easy operation, portable device, high accuracy, real-time monitoring, and rapid detection. According to the experimental results of flexible arrayed pH sensor and flexible arrayed glucose biosensor, the range of pH values from pH 1 to pH 13 has a good average sensitivity of 51.38 mV/pH and a linearity of 0.995, and the range of glucose solution concentration from 100 to 500 mg/dL has a good average sensitivity of 0.179 mV(mg/dL)-1 and a linearity of 0.999. The actual target in this paper is to provide a wireless sensing system for ion sensing and monitoring of human physiological data.

Sensing Characteristic of Arrayed Flexible Indium Gallium Zinc Oxide Lactate Biosensor Modified by Magnetic Beads

In this paper, we proposed an arrayed flexible lactate biosensor, and indium gallium zinc oxide (IGZO) was used as the sensing film. The screen-printed technology was used to miniaturize the reference electrode and conductive wires. Lactate dehydrogenase and nicotinamide adenine dinucleotide were used to deposit enzyme membrane on IGZO sensing film to catalyze lactate. In the measurement, the arrayed flexible IGZO lactate biosensor was immersed in the lactate solutions, which concentrations were 0.2, 0.7, 1.3, 2, and 3 mM, respectively. The average sensitivity and linearity of lactate biosensor were 114.900 mV/decade and 0.948, respectively.

The research of differential reference electrode arrayed flexible IGZO glucose biosensor based on microfluidic framework

This study used a fast, simple, and low-cost method to fabricate arrayed flexible glucose biosensor, and the glucose biosensor was integrated with microfluidic framework for investigating sensing characteristics of glucose biosensor at the dynamic conditions. The indium gallium zinc oxide (IGZO) was adopted as sensing membrane and it was deposited on aluminum electrodes / polyethylene terephthalate (PET) substrate by the radio frequency sputtering system. Then, we utilized screen-printed technology to accomplish miniaturization of glucose biosensor. Finally, the glucose sensing membrane was composed of glucose oxidase (GOx) and nafion, which was dropped on IGZO sensing membrane to complete glucose biosensor. According to the experimental results, we found that optimal sensing characteristics of arrayed flexible IGZO glucose biosensor at the dynamic conditions were better than at the static conditions. The optimal average sensitivity and linearity of the arrayed flexible IGZO glucose biosensor were 7.255 m...

A study of drift characteristic in arrayed flexible chlorine ion sensors with differential reference electrodes

The drift rate is change of voltage by time dependence, that is isothermal and fixed composition in the solution. In this study, we prepared arrayed flexible chlorine ion sensors which are fabricated by radio frequency sputtering technology and screen-printed technology to measure the drift in the different NaCl solutions, we obtained output voltage in variation concentrations from 10-5M to 1 M NaCl solutions over 12 hours, the drift rates of the chloride ion sensing devices are 1.122 mV/hr in 1 M NaCl solution, 1.192 mV/hr in 10-1 M NaCl solution, 2.869 mV/hr in 10-2 M NaCl solution, 1.529 mV/hr in 10-3M NaCl solution, 0.988 mV/hr in 10-4 M NaCl solution and 3.991 mV/hr in 10-5 M NaCl solution, respectively.

The research of the differential reference electrode arraved flexible IGZO pH sensor for different Ar/O 2 ratios

In this study, we used polyethylene terephthalate (PET) as substrate and we combined with screen-printed technology to achieve miniaturization of sensor. In order to avoid damaging for single sensing window, the sensor device had six sensing windows on polyethylene terephthalate (PET) substrate in this study. The six sensing windows could provide six measurement values, which could provide accurate measurement results. The sensing properties of indium gallium zinc oxide (IGZO) sensing membranes were changed by different sputtering parameters. Therefore, we changed Ar/O2 flow ratios of IGZO sensing membranes by the radio frequency sputtering system, which investigated about the sensing properties of differential reference electrode arrayed flexible IGZO pH sensor for different Ar/O2 flow ratios. Furthermore, we also researched on hysteresis effect and drift effect. The hysteresis experiments were carried out by two cycles of pH values, which were pH 7-11-7-3-7 and pH 7-3-7-11-7, respectively. The drift experiments were carried out by immersing IGZO sensor in pH3, pH7, pH11 buffer solutions for 12 hours, respectively. According to the experimental results, we found that Ar/O2 flow ratio of IGZO pH sensing membranes was set at 16/2 (in seem) by radio frequency sputtering system, which can have better performance. The sensitivity and linearity of the IGZO pH sensor were 54.737 mV/pH and 0.994 in Ar/O2 flow ambience of 16/2 (in sccm), respectively. The hysteresis values were 8.56 mV and 25.01 mV in cycles of pH 7-11-7-3-7 and pH 7-3-7-11-7 in Ar/O2 flow ambience of 16/2, respectively. The drift values were 1.06 mV/hr, 3.64 mV/hr, 6.04 mV/hr in pH3, pH7, pH11 buffer solutions from 5 to 12 hours in Ar/O2 flow ambience of 16/2, respectively. The experimental results demonstrated that IGZO sensing membrane was successfully applied to detect hydrogen ions.

Characteristic of arrayed flexible glucose biosensor integrated with the microfluidic device

In this study, the arrayed flexible glucose biosensor modified by graphene (GR) and integrated with the microfluidic device was developed. In order to prepare the glucose biosensor, graphene solution was first cast on the ruthenium dioxide (RuO2) electrode which were fabricated by radio frequency sputtering and screen-printed technique. Then, the composite of glucose oxidase (GOx) and nafion was dropped on RuO2 to complete preparation of the RuO2/Graphene/GOx-Nafion glucose biosensor. Finally, the modified glucose biosensor was combined with the microfluidic device to implement the glucose measurement at different flow rates from 5 μL/min to 30 μL/min. The experimental results showed that the RuO2/Graphene/GOx-Nafion glucose biosensor had higher sensitivity at 15 μL/min optimum flow rate, and the average sensitivity and linearity were 11.647 mV/mM and 0.995, respectively. Compare with other glucose biosensor measured at static conditions, the results demonstrated that the glucose biosensor had superior performance at the dynamic measurement.