Sensors 2011, 11(9), 8593-8610; https://doi.org/10.3390/s110908593
Real-Time Telemetry System for Amperometric and Potentiometric Electrochemical Sensors
1
Department of Electrical Engineering, National Cheng Kung University, Tainan 70101, Taiwan
2
Graduate Institute of Electrical Engineering, National Taipei University, Taipei 10617, Taiwan
3
Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan
4
Department of Chemical Engineering, Tatung University, Taipei 104, Taiwan
5
Department of Chemical Engineering, National Cheng Kung University, Tainan 70101, Taiwan
6
Department of Computer Science and Information Engineering, National Yunlin University of Science & Technology, Yunlin 64002, Taiwan
*
Author to whom correspondence should be addressed.
Received: 8 August 2011 / Revised: 29 August 2011 / Accepted: 1 September 2011 / Published: 2 September 2011
(This article belongs to the Special Issue Microprocessors and System-on-Chip)
Abstract
A real-time telemetry system, which consists of readout circuits, an analog-to-digital converter (ADC), a microcontroller unit (MCU), a graphical user interface (GUI), and a radio frequency (RF) transceiver, is proposed for amperometric and potentiometric electrochemical sensors. By integrating the proposed system with the electrochemical sensors, analyte detection can be conveniently performed. The data is displayed in real-time on a GUI and optionally uploaded to a database via the Internet, allowing it to be accessed remotely. An MCU was implemented using a field programmable gate array (FPGA) to filter noise, transmit data, and provide control over peripheral devices to reduce power consumption, which in sleep mode is 70 mW lower than in operating mode. The readout circuits, which were implemented in the TSMC 0.18-μm CMOS process, include a potentiostat and an instrumentation amplifier (IA). The measurement results show that the proposed potentiostat has a detectable current range of 1 nA to 100 μA, and linearity with an R2 value of 0.99998 in each measured current range. The proposed IA has a common-mode rejection ratio (CMRR) greater than 90 dB. The proposed system was integrated with a potentiometric pH sensor and an amperometric nitrite sensor for in vitro experiments. The proposed system has high linearity (an R2 value greater than 0.99 was obtained in each experiment), a small size of 5.6 cm × 8.7 cm, high portability, and high integration. View Full-Text
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MDPI and ACS Style
Wang, W.-S.; Huang, H.-Y.; Chen, S.-C.; Ho, K.-C.; Lin, C.-Y.; Chou, T.-C.; Hu, C.-H.; Wang, W.-F.; Wu, C.-F.; Luo, C.-H. Real-Time Telemetry System for Amperometric and Potentiometric Electrochemical Sensors. Sensors 2011, 11, 8593-8610.