An Integrated Portable Multiplex Microchip Device for Fingerprinting Chemical Warfare Agents

Abstract

The rapid and reliable detection of chemical and biological agents in the field is important for many applications such as national security, environmental monitoring, infectious diseases screening, and so on. Current commercially available devices may suffer from low field deployability, specificity, and reproducibility, as well as a high false alarm rate. This paper reports the development of a portable lab-on-a-chip device that could address these issues. The device integrates a polymer multiplexed microchip system, a contactless conductivity detector, a data acquisition and signal processing system, and a graphic/user interface. The samples are pre-treated by an on-chip capillary electrophoresis system. The separated analytes are detected by conductivity-based microsensors. Extensive studies are carried out to achieve satisfactory reproducibility of the microchip system. Chemical warfare agents soman (GD), sarin (GB), O-ethyl S-[2-diisoproylaminoethyl] methylphsophonothioate (VX), and their degradation products have been tested on the device. It was demonstrated that the device can fingerprint the tested chemical warfare agents. In addition, the detection of ricin and metal ions in water samples was demonstrated. Such a device could be used for the rapid and sensitive on-site detection of both chemical and biological agents in the future.

A Novel Planar Grounded Capacitively Coupled Contactless Conductivity Detector for Microchip Electrophoresis

“…The method of arranging a ground electrode between the sensing electrodes to reduce the stray capacitance has been widely applied [ 8 , 16 , 17 , 18 , 19 ]. However, it is generally considered that its effect on reducing stray capacitance is limited.…”

Determination of Nanoplastics Using a Novel Contactless Conductivity Detector with Controllable Geometric Parameters

“…The change in the conductance signal reflects the change in the measured substance flowing through the detection window and is expected to be applied to the quantitative detection of nanoplastics. The contactless conductivity detection method originated in the 1980s and was originally integrated into a capillary tube, , after which the emergence of a microfluidic chip C 4 D greatly increased the design creativity of contactless conductivity detectors. , By using microchip-based contactless conductivity detectors different scenarios, and their application has also developed from initial inorganic ions to the detection of environmental samples and complex samples of organisms. − Moreover, it has been proved that nonionic micelles (TX-100, 10%) could be tested using a capillary contactless conductivity detector and a negative response signal . C 4 D based on a microfluidic chip, with the advantages of achieving integration, being label-free, avoiding electrode or sample contamination, and so on, has great potential in on-site real-time analysis, enjoying remarkable development prospects.…”

PCB-C4D coupled with paper-based microfluidic sampling for the rapid detection of liquid conductivity

“…40 The inclusion of the grounding electrode between the sensing electrodes has been shown to effectively reduce stray capacitance, thereby augmenting signal-to-noise ratio and enhancing the quality of C 4 D signals. [41][42][43] The electrode dimensions are illustrated in Fig. 1a.…”