Redox-Magnetohydrodynamic Microfluidics Without Channels and Compatible; withElectrochemicalDetectionUnderImmunoassayConditions
by Weston, Melissa Christine; Nash, Christena K.; Fritsch, Ingrid
A unique capability of redox-magnetohydrodynamics (redox-MHD) for; handlingliquidsonasmallscalewasdemonstrated.A1.2muLsolution; plugwaspumpedfromaninjectionsitetoadetectorwithouttheneed; forachanneltodirecttheflow.Theredoxpumpingspeciesdidnot; interferewithenzymaticactivityinasolutioncompatiblewith; enzyme-linkedimmunoassays.Alkalinephosphatase(AP),acommonenzyme; label,convertedp-aminophenylphosphate(PAPP)top-aminophenol; (PAP(R))inthepresenceof2.5mMRu(NH3)(6)Cl-2and2.5mMRu(NH3)(6); Cl-3,in0.1MTrisbuffer(pH=9).AsolutionplugcontainingPAPP; (noAP)waspumpedthroughthesurroundingsolutioncontainingAP(no; PAPP),andtheenzymaticallygeneratedPAPRwaseasilydetectedand; distinguishableelectrochemicallyfromthepumpingspecieswithsquare; wavevoltammetrydownto0.1mMconcentrations.Thetestdevice; consistedofasiliconchipcontainingindividuallyaddressable; microbandelectrodes,placedona0.5TNdFeBpermanentmagnetwiththe; fieldorientedperpendiculartothechip.A8.0mmwidex15.5mmlong; x1.5mmhighvolumeofsolutionwascontainedbya; poly(dimethylsiloxane)gasketandcappedwithaglassslide.A; steady-statefluidvelocityofsimilarto30mum/swasgeneratedina; reinforcingflowconfigurationbetweenoppositelypolarizedsetsof; pumpingelectrodeswithsimilarto2.1muA.
- Journal
- Analytical Chemistry
- Volume
- 82
- Issue
- 17
- Year
- 2010
- Start Page
- 7068
- ISBN/ISSN
- 1520-6882; 0003-2700
- PMID
- 20681513
- DOI
- 10.1021/ac101377a