LAUSR

Abstract The laser-induced modification of polyimide substrates to yield conductive graphitised tracks sensitive to the solution pH is investigated. The influence of laser output and operating characteristics on the surface morphology and the consequential impact on electrochemical properties have been evaluated. Several sensor formats have been pursued using both potentiometric and voltammetric methodologies and found to provide a stable means of determining pH. While the potentiometric system was found to provide sub-Nernstian responses, the voltammetric system employing a riboflavin (vitamin B2) redox probe was found to exhibit classic Nernstian profiles (56 mV/pH). The versatility of the laser patterning on polyimide is shown to yield a mechanically flexible double-sided probe that could be suitable for use in a wide variety of clinical applications.