Defense Date


Document Type


Degree Name

Doctor of Philosophy



First Advisor

Julio Alvarez


This work deals with the development of a new label-free detection technique called Pulsed Streaming Potential (PSP). Its novelty relies on the adaptation of a classical electrokinetic phenomenon (streaming potential) into a tool which can evaluate molecular interplay in label-free fashion. Implementation of PSP to microfluidic platforms allowed the label-free sensing of binding events to plastic (modified and unmodified) surfaces. It was demonstrated the use of real time PSP in plastic microfluidic platforms for determination of kinetic parameters of the interaction of proteins and plastic surfaces. Moreover, initial change of PSP after adsorption of proteins showed to be proportional to the bulk concentration of proteins and it was used for quantification of Lysozyme in the nanomolar range. Several approaches were studied to manipulate the surface of microfluidic channels in order to improve selectivity of PSP through reduction of non-specific adsorption. These approaches included the fabrication of composite surface of polyacrilic acid (PAA) and polyethylene glycol acrylate (PEGA) on cyclic olefin copolymer microchannels, as well as adsorption of nanospheres on COC-PEGA channels.


© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

May 2011

Available for download on Thursday, May 13, 2021

Included in

Chemistry Commons