Spin-assembled nanofilms for gaseous oxygen sensing

A nanofilm optical sensor for detection and measurement of gaseous oxygen was developed and shown to quantify oxygen concentration over a wide range of conditions. The sensor was fabricated using the spin assembly of an oxygen-sensitive dye entrapped in a dye/polyion interpolyelectrolyte complex. The sensor demonstrated good correlation to the Stern–Volmer relationship, with linear decay in sensitivity of approximately 1.6% per week. The system also demonstrated some level of pressure sensitivity and corresponding variation of the Stern–Volmer constant, facilitating the possible use of the system as a pressure sensor. Oxygen concentration of the sensor was linear over a range of 0–100%, with a resolution of 0.2%. The high sensitivity, inherent linearity and flexibility of this sensor make it suitable for a variety of applications, including biological respiration studies, environmental monitoring, and cell cultures.