Optical sensing membranes, devices and methods for simultaneous detection of two or more parameters of dissolved oxygen concentration, pH and temperature

An optical sensing membrane for simultaneous detection of three parameters of dissolved oxygen concentration, pH and temperature, comprising a support, and a homogeneous solution immobilized on the support,

• wherein the homogeneous solution comprises three fluorescent dyes and is made from a homogeneous mixture solution containing:
• tris(4,7-dipenyl-1,10-phenanthroline) ruthenium (II) complex (Rudpp);
• 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS);
• either Quantum dots (Qds) or rhodamine B, and wherein a weight ratio of Rudpp:HPTS:Quantum dots is 0.5˜1.5:0.5˜1.5:15˜25, or a weight ratio of Rudpp:HPTS:rhodamine B is 0.5˜1.5:0.5˜1.5:0.0001˜0.001;
• and wherein the homogenous solution immobilized on the support constitutes a single sensor, and the three parameters of dissolved oxygen, pH and temperature are simultaneously measured by means of intensities of a single spectrum from the single sensor.