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Journal of Sensors
Volume 2017 (2017), Article ID 8797435, 13 pages
https://doi.org/10.1155/2017/8797435
Research Article

A Mobile-Based High Sensitivity On-Field Organophosphorus Compounds Detecting System for IoT-Based Food Safety Tracking

1Center of Micro-Nano Systems, Fudan University, Shanghai 200433, China
2State Key Laboratory of ASIC & Systems, Fudan University, Shanghai 201203, China
3School of Electronic Engineering, Xidian University, Xi’an 710126, China
4IME, ICT, KTH Royal Institute of Technology, Stockholm, Sweden

Correspondence should be addressed to Yajie Qin; nc.ude.naduf@niqeijay and Guoping Chen; nc.ude.naduf@elppanehcpg

Received 4 October 2016; Accepted 13 December 2016; Published 20 February 2017

Academic Editor: Xiongchuan Huang

Copyright © 2017 Han Jin et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A mobile-based high sensitivity absorptiometer is presented to detect organophosphorus (OP) compounds for Internet-of-Things based food safety tracking. This instrument consists of a customized sensor front-end chip, LED-based light source, low power wireless link, and coin battery, along with a sample holder packaged in a recycled format. The sensor front-end integrates optical sensor, capacitive transimpedance amplifier, and a folded-reference pulse width modulator in a single chip fabricated in a 0.18 μm 1-poly 5-metal CMOS process and has input optical power dynamic range of 71 dB, sensitivity of 3.6 nW/cm2 (0.77 pA), and power consumption of 14.5 μW. Enabled by this high sensitivity sensor front-end chip, the proposed absorptiometer has a small size of 96 cm3, with features including on-field detection and wireless communication with a mobile. OP compound detection experiments of the handheld system demonstrate a limit of detection (LOD) of 0.4 μmol/L, comparable to that of a commercial spectrophotometer. Meanwhile, an android-based application (APP) is presented which makes the absorptiometer access to the Internet-of-Things (IoT).