Patent ID: 8685745

Claim:
A method of manufacturing a multilayered optical sensing patch, comprising the steps of: (a) soaking a porous polymer support membrane in a pH buffer composition, dimethyl formamide, or triethylamine in water solution; (b) placing the porous polymer support membrane in a solution comprising a reactive indicator, and allowing the porous polymer support membrane to soak in the solution for a time period sufficient to allow the reactive indicator to covalently bond to free amines on the porous polymer support membrane; (c) removing any unbound reactive indicator from the polymer sensing membrane layer by decanting the solution and/or rinsing the solution from the porous polymer support membrane; and (d) laminating a heat sealable polymer substrate film to the porous polymer support membrane layer, having pores therein, using a combination of heat and pressure; said heat sealable polymer substrate film having an optical transparency of at least 50%; said laminating comprising heating the heat sealable polymer substrate film and the porous polymer support membrane layer to a temperature higher than an onset melting point of the heat sealable polymer substrate film and lower than a melt temperature of the porous polymer support membrane layer.