Portable integrated microfluidic analytical platform for the monitoring and detection of nitrite

• Published in: Talanta (Oxford) 2013-11, Vol.116, p.997-1004
• Main Authors: Czugala, Monika, Fay, Cormac, O'Connor, Noel E., Corcoran, Brian, Benito-Lopez, Fernando, Diamond, Dermot
• Format: Article
• Language: English
• Subjects: Biomimetic microvalve; Color; Electrochemical Techniques; Ethylenediamines - chemistry; Fresh Water - chemistry; Light; Limit of Detection; Low cost; Low-power analytical platform; Mathematical analysis; Microfluidic Analytical Techniques - economics; Microfluidic Analytical Techniques - instrumentation; Microfluidic device; Microfluidics; Monitoring; Nitrite determination; Nitrites; Nitrites - analysis; PEDD detector; Photoswitchable actuators; Platforms; Portability; Sulfanilamides - chemistry; Water Pollutants, Chemical - analysis; White light
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2013.07.058

A wireless, portable, fully-integrated microfluidic analytical platform has been developed and applied to the monitoring and determination of nitrite anions in water, using the Griess method. The colour intensity of the Griess reagent nitrite complex is detected using a low cost Paired Emitter Detector Diode, while on-chip fluid manipulation is performed using a biomimetic photoresponsive ionogel microvalve, controlled by a white light LED. The microfluidic analytical platform exhibited very low limits of detection (34.0±0.1μgL−1 of NO2−). Results obtained with split freshwater samples showed good agreement between the microfluidic chip platform and a conventional UV–vis spectrophotometer (R2=0.98, RSD=1.93% and R2=0.99, RSD=1.57%, respectively). The small size, low weight, and low cost of the proposed microfluidic platform coupled with integrated wireless communications capabilities make it ideal for in situ environmental monitoring. The prototype device allows instrument operational parameters to be controlled and analytical data to be downloaded from remote locations. To our knowledge, this is the first demonstration of a fully functional microfluidic platform with integrated photo-based valving and photo-detection. •Wireless, portable, fully-integrated microfluidic analytical platform.•Monitoring and determination of nitrite anions in water, using the Griess method.•Integrated low cost Paired Emitter Detector Diode.•On-chip fluid manipulation using a biomimetic photoswitchable ionogel microvalve.•Microfluidic platform coupled with integrated wireless communications.