Preparation and application of dye-functionalized flexible upconversion-luminescence solid-phase sensor

A method of preparing a dye-functionalized flexible upconversion-luminescence solid-phase sensor, comprising:

• (S1) mixing ytterbium chloride hexahydrate, yttrium chloride hexahydrate, and thulium chloride hexahydrate uniformly in a first solvent under ultrasonication;
• adding oleic acid and 1-octadecene followed by a first stirring and cooling to room temperature;
• dropwise adding sodium hydroxide, ammonium fluoride and a second solvent followed by sealing, heating, a second stirring, cooling to room temperature, and centrifugation to collect a precipitate;
• and rinsing the precipitate with a mixture of cyclohexane and ethanol followed by drying to give an upconversion-luminescence nanoparticle;
• wherein the first solvent and the second solvent are both methanol;
• (S2) mixing a polydimethylsiloxane monomer and a curing agent to obtain a mixture;
• adding the upconversion-luminescence nanoparticle to the mixture followed by stirring to form a gel;
• subjecting the gel to vacuum degassing, casting in a mold and vacuum degassing;
• pressing the mold with a cover plate followed by drying, curing, and cooling to room temperature to obtain an upconversion-luminescence nanoparticle-doped solid-phase sensor;
• and
• (S3) mixing sodium periodate, benzyl alcohol, acrylic acid and water to form a first solution;
• immersing the upconversion-luminescence nanoparticle-doped solid-phase sensor into the first solution followed by ultraviolet (UV) irradiation and a first rinsing to obtain a carboxyl-grafted upconversion-luminescence nanoparticle-doped solid-phase sensor;
• and
• mixing 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, hydroxysuccinimide, distilled water and a 2-(N-morpholino) ethanesulfonic acid buffer in a ratio of 10-30 (mg):
• 5-15 (mg):
• 0.5-1.5 (mL):
• 0.3-0.6 (mL) to form a second solution;
• immersing the carboxyl-grafted upconversion-luminescence nanoparticle-doped solid-phase sensor into the second solution for incubation for 2 h followed by a second rinsing with distilled water to obtain a carboxyl-activated upconversion-luminescence nanoparticle-doped solid-phase sensor;
• immersing the carboxyl-activated upconversion-luminescence nanoparticle-doped solid-phase sensor into a pararosaniline solution for incubation for 11-13 h followed by a third rinsing with distilled water to obtain the dye-functionalized flexible upconversion-luminescence solid-phase sensor;
• wherein a concentration of the pararosaniline solution is 0.01-0.05 mg/mL.