title: Highly sensitive and reusable Pt-black microfluidic electrodes for long-term electrochemical sensing.
abstract: Highly sensitive, long-term stable and reusable microfluidics electrodes have been fabricated and evaluated using H2O2 and hydroquinone as model analytes. These electrodes composed of a 300 nm Pt-black layer situated on a 5 μm thick electrodeposited Au layer, provide effective protection against electrooxidation of an underlying chromium adhesion layer. Using repeated cyclic voltammetric (CV) sweeps in flowing buffer solution, highly sensitive Pt-black working electrodes were realized with five- (four-) decade linear dynamic range for H2O2 (hydroquinone) and low detection limit of 10 nM for H2O2 and 100 nM for hydroquinone. Moreover, high sensitivity for H2O2 was demonstrated at low (0.3 V vs. Ag/AgCl) oxidation potentials, together with long-term stability and reusability for at least 30 days. Microfluidic flow was employed for desorption and reactivation of the nominally planar Pt-black electrodes. Such electrocatalytic surface architecture should be appropriate for long-term electrochemical detection of various molecules and biomolecules as well as in reusable immunoassay configurations.
authors.affiliation: Nanomaterials Optoelectronics Laboratory, Polymer Program, Institute of Materials Science, Department of Chemistry, University of Connecticut, Storrs, CT 06269, United States.
authors.forename: Liangliang
authors.initials: L
authors.lastname: Qiang
authors.forename: Santhisagar
authors.initials: S
authors.lastname: Vaddiraju
authors.forename: James F
authors.initials: JF
authors.lastname: Rusling
authors.forename: Fotios
authors.initials: F
authors.lastname: Papadimitrakopoulos
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017743:Equipment Reuse; D017022:Flow Injection Analysis / Q000295:instrumentation*; D007118:Immunoassay / Q000295:instrumentation*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D010984:Platinum / Q000737:chemistry*
chemical_list: D010984:Platinum