Optofluidic integrated bragg grating chemical sensor: Utilising a sodium-selective receptor surface to enhance detection

A second-generation sensor is proposed that aims to enhance both the selectivity and sensitivity of the crown ether system. This sensor uses a calix(4)crown-based ionophore, a receptor that offers a greater affinity for sodium over the simple crown ether receptor. When combined with a switchable dye, this chromoionophore will selectively amplify the refractive index change upon binding sodium over other cations. We shall present the latest developments towards a highly sensitive and selective sodium sensor using a calix(4)crown-based chromoionophore receptor surface.