A novel microfluidic flow-injection analysis device with fluorescence detection for cation sensing. Application to potassium

AbstractA microfabricated device has been developed for fluorimetric detection of potassium ions without previous separation. It is based on use of a fluorescent molecular sensor, calix–bodipy, specially designed to be sensitive to and selective for the target ion. The device is essentially made of a Y-shape microchannel moulded in PDMS fixed on a glass substrate. A passive mixer is used for mixing the reactant and the analyte. The optical detection arrangement uses two optical fibres, one for excitation by a light-emitting diode, the other for collection of the fluorescence. This system enabled the flow-injection analysis of the concentration of potassium ions in aqueous solutions with a detection limit of 0.5 mmol L−1 and without interference with sodium ions. A calibration plot was constructed using potassium standard solutions in the range 0–16 mmol L−1, and was used for the determination of the potassium content of a pharmaceutical pill. FigurePhotography of the microfluidic channel showing the ridges in the PDMS substrate at the top of the channel

[1]  H. Gampp,et al.  Calculation of equilibrium constants from multiwavelength spectroscopic data-I Mathematical considerations. , 1985, Talanta.

[2]  A. Manz,et al.  Micro total analysis systems. 1. Introduction, theory, and technology. , 2002, Analytical chemistry.

[3]  Martin Pumera,et al.  Contactless conductivity detector for microchip capillary electrophoresis. , 2002, Analytical chemistry.

[4]  P. Fielden,et al.  Single electrode conductivity detection for electrophoretic separation systems , 1999 .

[5]  Ruey-an Doong,et al.  Simultaneous determination of pH, urea, acetylcholine and heavy metals using array-based enzymatic optical biosensor. , 2005, Biosensors & bioelectronics.

[6]  M. Madou,et al.  Fluorescent ion-selective optode membranes incorporated onto a centrifugal microfluidics platform. , 2002, Analytical chemistry.

[7]  I. Mezić,et al.  Chaotic Mixer for Microchannels , 2002, Science.

[8]  L. Sarro,et al.  Capillary electrophoresis with on‐chip four‐electrode capacitively coupled conductivity detection for application in bioanalysis , 2001, Electrophoresis.

[9]  I. Leray,et al.  A highly selective fluorescent molecular sensor for potassium based on a calix[4]bisazacrown bearing boron-dipyrromethene fluorophores , 2005 .

[10]  M. Macka,et al.  Determination of inorganic ions using microfluidic devices , 2004, Electrophoresis.

[11]  Albert van den Berg,et al.  New approaches for fabrication of microfluidic capillary electrophoresis devices with on‐chip conductivity detection , 2001, Electrophoresis.

[12]  E. Bakker,et al.  Mass-produced lonophore-based fluorescent microspheres for trace level determination of lead ions. , 2002, Analytical chemistry.

[13]  Takehiko Kitamori,et al.  On-Chip Integration of Neutral Ionophore-Based Ion Pair Extraction Reaction , 2001 .