SURFACE CHARACTERISTICS OF OPTICAL CHEMICAL SENSORS

The efficiency of optical sensors (optrodes) as determined and improved by various surface-structure features is discussed. pO2 and pH optrode models are employed to demonstrate the increased sensitivity and/or reduced response times upon: (1) increasing the distance between the surface of the solid support, e.g., silica, and the reagent; (2) producing a 'comfortable' microenvironment for the analyte, i.e., one resembling its polarity-, and/or (3) applying a surface with the optimal pore size. The sensitivities of the pO2 and/or pH sensors are enhanced by a factor of 3.6-4.3, while the response time for a pH sensor is reduced from 60-80 s to 2-5 s.