Date Published: March 6, 2019
Publisher: Public Library of Science
Author(s): Xiaojin Luo, Xuesong Yao, Yalei Zhang, Xingwen Zheng, Guangming Xie, Yue Cui, Rui Xiong.
The development of new signal systems for electrical biosensors could provide exciting new opportunities for biomedical analysis, pollutant monitoring, and explosive detection. The signal systems for commercial portable sensors involve the integration of a battery and a circuit conditioning system to power an amperometric biosensor. However, this increases the size and complexity of the entire system. In this study, we develop a simple amperometric biosensor that is directly powered by a button cell battery for the detection of lactate. A two-electrode sensing transducer was printed on cardboard or integrated on a ring. It was directly powered by a button cell battery, and connected to a multimeter for current measurement. This sensor showed a sensitive detection range of 0.04762–9.21429 mM and short measuring time of 2 min. These results show that this system can achieve an excellent sensing performance, and the construction of this new sensing system directly powered by a button cell battery offers a new method for further developing a wide range of miniaturized, flexible, portable, or wearable sensing systems, and these could be used in detecting various analytes that are important in medical diagnosis and environmental monitoring.
Amperometric biosensing systems have been widely used for healthcare applications [1–3]. In such sensors, the sensing transducer consists of three electrodes: working, reference, and counter electrodes [1–3]. The sensor configuration could have three or two electrodes, a bioreceptor is generally immobilized on the working electrode, and all electrodes are covered by buffer solution [4–6]. In a two-electrode sensor, one electrode functions as both the reference and the counter electrodes . The sensor is generally powered by a signal system consisting of a battery and a circuit conditioning system [1, 2]. The latter regulates the battery voltage to produce a suitable output power for the sensor. Currently, micrometer or millimeter-scale sensing transducers can be fabricated or printed [1, 6]. However, the entire sensing system cannot be too small owing to the size of the battery and circuit conditioning system.
In this study, we have developed a sensor system powered by a button battery and compared its performance with that of a traditional potentiostat for detecting lactate. We found that both systems showed similar sensing performances. By longitudinally comparing the effect of experimental conditions such as the buffer concentration and the voltage on the sensing performance, we verified that the battery-powered sensor shows an excellent detection performance, making it a promising alternative for electrochemical measurements in the future. The battery-powered sensor is greatly simplified in size and structure relative to the potentiostat, allowing us to mount it on items such as a little ring to detect the characteristics of sweat ubiquitously. We expect that this study could open up significant avenues for developing new sensing systems and advance related biomedical and environmental applications.