Development of chemical sensors using polymer optical waveguides fabricated with DNA

A number of studies are currently focused on using polymers derived from salmon DNA as the primary ingredient in the design of optical waveguide devices. Although the Ion term goal is to develop optical devices for rapid chemical and biosensing, this work was aimed specifically at studying the response of a planar DNA waveguide to anmonia in nitrogen and air with controlled amounts of humidity at ambient temperatures. This follows the work of S. S. Sarkisov et al. who used PMMA and other polymer films doped with the indicator dye bromocresol purple (BCP). These devices are characterized by absorption sensitivities of the order 0.1 dB attenuation of the transmitted light signal per 100 ppm change in the NH3 concentration with response times of better than 1 ms and can be recycled with no loss of sensitivity. The performances of waveguide devices using films fabricated with high and low molecular weight DNA with BCP are compared to BCP-doped PMMA devices.