title: Portable integrated microfluidic analytical platform for the monitoring and detection of nitrite.
abstract: 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±0.1 μg L(-1) of NO2(-)). Results obtained with split freshwater samples showed good agreement between the microfluidic chip platform and a conventional UV-vis spectrophotometer (R(2)=0.98, RSD=1.93% and R(2)=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.
authors.affiliation: CLARITY: Centre for Sensor Web Technologies, National Centre for Sensor Research, Dublin City University, Dublin, Ireland.
authors.forename: Monika
authors.initials: M
authors.lastname: Czugala
authors.forename: Cormac
authors.initials: C
authors.lastname: Fay
authors.forename: Noel E
authors.initials: NE
authors.lastname: O'Connor
authors.forename: Brian
authors.initials: B
authors.lastname: Corcoran
authors.forename: Fernando
authors.initials: F
authors.lastname: Benito-Lopez
authors.forename: Dermot
authors.initials: D
authors.lastname: Diamond
mesh_terms: D003116:Color; D055664:Electrochemical Techniques; D005029:Ethylenediamines / Q000737:chemistry; D005618:Fresh Water / Q000737:chemistry*; D008027:Light; D057230:Limit of Detection; D046210:Microfluidic Analytical Techniques / Q000191:economics / Q000295:instrumentation*; D009573:Nitrites / Q000032:analysis*; D013424:Sulfanilamides / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D005029:Ethylenediamines; C095000:Griess reagent; D009573:Nitrites; D013424:Sulfanilamides; D014874:Water Pollutants, Chemical
keywords: Biomimetic microvalve; Low-power analytical platform; Microfluidic device; Nitrite determination; PEDD detector; Photoswitchable actuators