Cheng LJ, Chang HC. Microscale pH regulation by splitting water.
BIOMICROFLUIDICS 2011;
5:46502-465028. [PMID:
22121407 PMCID:
PMC3223509 DOI:
10.1063/1.3657928]
[Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Accepted: 10/13/2011] [Indexed: 05/09/2023]
Abstract
We present a simple, flexible approach for pH regulation in micro-chambers by injecting controllable amounts of protons and hydroxide ions via field-enhanced dissociation of water molecules. Under a DC voltage bias, the polymeric bipolar membranes integrated in microfluidics devices generate and separate H(+) and OH(-) ions without gas production or contaminant generation resulting from electron-transfer reactions. Robust local on-chip pH and pH gradients are sustained with no need of additional acidic∕basic solutions that dilute analyte concentrations. The method could provide a better strategy for pH control in microfluidics.
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