Development of an integrated microfluidic instrument for unattended water‐monitoring applications

Abstract

Field-deployable detection technologies in the nation's water supplies have become a high priority in recent years. The unattended water sensor is presented which employs microfluidic chip-based gel electrophoresis for monitoring proteinaceous analytes in a small integrated sensor platform. The instrument collects samples directly from a domestic water flow. The sample is then processed in an automated microfluidic module using in-house designed fittings, microfluidic pumps and valves prior to analysis via Sandia's microChemLab module, which couples chip-based electrophoresis separations with sensitive LIF detection. The system is controlled using LabVIEW software to analyze water samples about every 12 min. The sample preparation, detection and data analysis has all been fully automated. Pressure transducers and a positive control verify correct operation of the system, remotely. A two-color LIF detector with internal standards allows corrections to migration time to account for ambient temperature changes. The initial unattended water sensor prototype is configured to detect protein biotoxins such as ricin as a first step toward a total bioanalysis capability based on protein profiling. The system has undergone significant testing at two water utilities. The design and optimization of the sample preparation train is presented with results from both laboratory and field testing.

Automated analysis of mouse serum peptidome using restricted access media and nanoliquid chromatography–tandem mass spectrometry

“…MAPS [25,27] joins commercial and customized hardware components (valves, pumps, cartridges, UV detector, autosampler and fraction collector) to perform on-line processing and fractionation of complex biological samples. The Spark autosampler (Spark, Emmen, The Netherlands), the NE-500 OEM syringe pumps (New Era Pump Systems, Wantagh, NY), the UVVIS 200 Linear detector (Reno, NV), the Rheodyne selection valve (IDEX, Oak Harbor, WA) and the BioRad 100 fraction collector (BioRad, Hercules, CA) are commercially available.…”

“…Custom software enables rapid communication with individual modules for an essentially unlimited number of serial and parallel processing steps. The MAPS platform bridges micro and mesofluidic applications (10-10,000 l) and has been used for sample processing in fully integrated systems for environmental analysis [25][26][27].…”

“…In this study we demonstrate use of a modular automated processing system (MAPS) [25][26][27] for continuous analysis of small-volume (75 l) mouse serum samples. In our system, RAM-RP and buffer exchange (BE) modules integrate selective separation of the serum peptidome and delivery of fractions in matrices/buffers ready for digestion and mass spectrometric analysis.…”

Smart portable electrophoresis instrument based on multipurpose microfluidic chips with electrochemical detection

“…Different papers have been published using these microdevices for environmental monitoring and control , clinical , pharmaceutical , and agro‐food areas. The above‐mentioned features, give an enormous potential to this analytical technique.…”

“…A wireless mobile unit, called “lab‐on‐a‐robot”, has been used to perform environmental analysis . Recently, an unattended water sensor (UWS) prototype has been designed to detect proteins biotoxins from domestic water flow. Other portable CE instruments with amperometric, potentiometric, and conductivity detection have been also described in the bibliography .…”