Development of a sensitive, low-cost and user-friendly centrifugal microfluidic cartridge for multi-analyte environmental monitoring
Glennon, Thomas, Floris, Patrick, O'Quigley, Conor, McNamara, Eoghan, Yang, Yang, Fraser, Kevin J.ORCID: 0000-0002-9718-5405, Smeaton, Alan F.ORCID: 0000-0003-1028-8389, Ducrée, JensORCID: 0000-0002-0366-1897 and Diamond, DermotORCID: 0000-0003-2944-4839
(2014)
Development of a sensitive, low-cost and user-friendly centrifugal microfluidic cartridge for multi-analyte environmental monitoring.
In: Sensors in the Environment 2014, 15-16 Oct 2014, Imperial College, London, UK.
This paper describes the development of a simple centrifugal cartridge for the analysis of nitrite, ammonia and phosphate from a water sample. The cartridge is operated in combination with the Centrifugal Microfluidic Analysis System (CMAS)[1] which incorporates rotational control with optical and communication components for portable analysis of environmental and biomedical samples[1,2]. An LED and a photodiode allow colorimetric determination of specific analytes depending on which reagent-based analytical method is employed. Bluetooth wireless communications provides automatic uploading of analytical data to cloud-based information systems.
Microfluidic discs consisting of three PMMA (Poly(methyl methacrylate)) layers bonded together by two PSA (Pressure Sensitive Adhesive) layers were prepared. The sample was transported from a single chamber to three aliquoting chambers at a low rotational frequency prior to the actuation of dissolvable film valves[3] at an increased rotational frequency to facilitate sample transport to reaction/detection chambers.
Ammonia standards were analysed using a modified Berthelot method, the stannous chloride method was used to detect orthophosphate levels while a diazotization method was employed to determine nitrite concentration. Photodiode analysis on the CMAS platform obtained LOD’s of 0.233 ppm for ammonia and 0.189 ppm for orthophosphate and 50 ppb for nitrite.